MK3.9S

<h3>Prusa CORE One Assembled shipping table</h3>
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<p><strong>Batch number (Assembled)</strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center;">
<p><strong>Estimated shipping from:</strong></p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 10px;">
<p>1</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 10px;">
<p>January 31. 2025</p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>2</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>February 12. 2025</p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>3</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>February 18. 2025</p>
</td>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>4</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>February 25. 2025</p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>5</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>March 3. 2025</p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>6</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>March 7. 2025</p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>7</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>March 12. 2025</p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>8</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>March 18. 2025</p>
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<tr style="height: 51px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>9</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>March 21. 2025</p>
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<h3><span style="font-size: 20px;">Current lead time estimates for new orders</span></h3>
<p><span style="color: #e67e23;"><strong>Updated: February 11th, 2025 </strong></span></p>
<p><em>The dates are only an estimation at the date of update, specified above, and rely on the actual</em> production. <em>We're doing our best but please be aware that it can shift for the lead time products. We will update here and on the product pages accordingly.</em></p>
<p>The lead time estimate applies to standalone products, other products in the order may increase the lead time.</p>
<p>If you've ordered a product in a bundle, the lead time of the order is set based on the product in the bundle with the longest lead time.</p>
<p></p>
<table class="table" style="border-collapse: collapse; height: 930.875px; border-style: ridge; width: 100%;" border="1">
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<h4>Product</h4>
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<td style="height: 60.875px; width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center;">
<h4>Lead time</h4>
</td>
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<tr style="height: 72px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>MK4 to MK4S upgrade</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p>1-2 weeks</p>
</td>
</tr>
<tr style="height: 51px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MK3.9 to MK3.9S upgrade</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>1 week</p>
</td>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MK3S/+ to MK4S upgrade</strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>1-2 weeks</strong></p>
</td>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MK3S/+ to MK3.9S upgrade</strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>1-2 weeks</strong></p>
</td>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MK3S/S+ to MK3.5S</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>1-2 weeks</p>
</td>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>Original Prusa MK4S</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>1 week</p>
</td>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>Original Prusa MK4S kit</strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>2-3 weeks</strong></p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>Original Prusa XL<br /></strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>1-3 weeks<br />(depending on variant)</p>
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</tr>
<tr style="height: 72px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>Original Prusa MMU3 upgrade kit<br />(for MK3.9/S &amp; MK4/S)<br /></strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p>1-2 weeks</p>
</td>
</tr>
<tr style="height: 72px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>Original Prusa MMU2S to MMU3 upgrade<br />(for MK3.9/S &amp; MK4/S)</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p>1-2 weeks</p>
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<tr style="height: 72px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>Original Prusa MMU3 assembled unit<br />(MK3.9/S &amp; MK4/S)</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p>1-2 weeks</p>
</td>
</tr>
<tr style="height: 72px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>Original Prusa MMU3 assembled unit<br />(MK3S+ &amp; MK3.5/S)</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p>1-2 weeks</p>
</td>
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<tr style="height: 51px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>Original Prusa XL Enclosure</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>2-3 weeks</p>
</td>
</tr>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>Original Prusa MINI Enclosure</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>1-2 weeks</p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>Original Prusa MK Enclosure </strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p>1-2 weeks</p>
</td>
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</tbody>
</table>
<p>You can find your order shipping date in the order detail section in our shop.</p>
<div class="note-callout">All products purchased in our <a href="https://shop.prusa3d.com/">online store</a> are currently being shipped from the<strong> Czech Republic, </strong>a member state of the <strong>European Union, customs charges may apply for shipments to countries outside of the EU!</strong> Please see our advisory article <a href="http://help.prusa3d.com/article/vat-value-added-tax-customs-fees_1505#orders-outside-eu">here</a>.</div>

Shipping information

Infill patterns

<div class="warning-callout">This is an&nbsp;<strong>advanced calibration</strong>, recommended only to&nbsp;<strong>experienced users</strong>.</div>
<p>The Extrusion Multiplier allows the fine-tuning of the extrusion flow rate - simply described as&nbsp;<strong>how much filament comes out of the nozzle</strong>. In other words, the&nbsp;<strong>Extrusion Multiplier</strong>&nbsp;setting in PrusaSlicer and the&nbsp;<strong>Flow rate</strong>&nbsp;setting in printer firmware are two ways to adjust the same thing, however, adjusting one of those two settings will not influence the value of the other.</p>
<p><strong>This procedure is not necessary with a new printer coming from the factory</strong>, but rather applies for specific applications and filaments. The ideal value is different for every type of material and every color. It can even differ from spool to spool. Bear this in mind if you change type and brand of filament often or use cheap no-name brands.</p>
<div class="note-callout">Total flow rate = <strong>Flow multiplier</strong> in firmware (M221) x <strong>Extrusion multiplier</strong> in PrusaSlicer. For those interested in diving deeper, PrusaSlicer uses the same <a href="https://manual.slic3r.org/advanced/flow-math">Flow math as Slic3r</a>.</div>
<h3><strong>How to spot an issue</strong></h3>
<p>This calibration is used to fix two common problems:</p>
<ul>
<li><strong>Overextrusion</strong> - Too much material is extruded (flow is too high). It causes scarring of bottom layers and unnecessary material buildup on top layers.</li>
<li><strong>Minor under extrusion</strong>&nbsp;- Not enough material is extruded (flow is too low). It causes small gaps that appear between layer lines or perimeters.</li>
</ul>
<p><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-600x282.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-800x376.jpg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-300x141.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-768x361.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-1536x721.jpg 1536w" alt="" width="852" height="400"></p>
<p><strong>Overextrusion</strong> is a common problem with many filament brands. It's especially problematic when you're trying to glue two parts of the model. <strong>If the top layer is over extruded, you'll end up with an uneven surface that will prevent a seamless connection between the two pieces.</strong></p>
<h3><strong>How to do the calibration</strong></h3>
<p>In PrusaSlicer, navigate to <span class="key">Filament Settings</span> and look for Extrusion Multiplier. The default setting (for PLA) is 1, this value represents a percentage, 1 = 100%, 0.95 = 95% etc. Usually, the adjusted values can be between 0.9 and 1.1. To adjust it, simply rewrite the value.</p>
<p><img decoding="async" style="max-height: 200px; display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusuki/prusuki-images/image-2019-1-15-12-55-6.png" data-hd-height="200px"></p>
<p>In the printer menu, during a print, go to the Tune menu and then choose Flow. Again, the usual values can range between 90 and 110, although that does not mean you can't go above or below that.</p>
<h4>Which method should I use?</h4>
<p>There are two methods you can use to calibrate the Extrusion Multiplier, and we'll cover both of them in this article:</p>
<ul>
<li><strong>Precise Method</strong>&nbsp; -&nbsp; using precision tools such as calipers or micrometers.</li>
<li><strong>Visual Method&nbsp;</strong>&nbsp;- an easy method based on observing the visual properties of your models.</li>
</ul>
<p>The choice of the method depends entirely on your preferences; in the end, both yield similar results. Even the visual method will enable you to have perfectly fitting parts with smooth &amp; flat top layers.</p>
<h4>Precise Method</h4>
<div class="note-callout">Please note that the following guide is based on <strong>default</strong> PrusaSlicer 0.4 nozzle profiles, with a layer height of 0.1mm - 0.2mm. This means that:<br />
- Nozzle size = 0.4<br />
- Extrusion width =&nbsp;0.45<br />
- Basic materials (PLA, ABS, PETG) Extrusion Multiplier = 1<br />
<strong>If you wish to calibrate the printer with a bigger/smaller nozzle or layer heights above 0.2, then you will need to adjust these values as well.</strong></div>
<ol>
<li>Download the <a href="https://cdn.help.prusa3d.com/wp-content/uploads/2021/04/cube-40-40-40.zip">Precision Method Cube STL</a>.</li>
<li>Slice it using the Vase Mode and your most-often used layer height and print it. You can find Vase mode (Print Settings →&nbsp; Layers and perimeters →&nbsp; Spiral vase).</li>
<li>Make three or more measurements in the middle of each wall and calculate the overall average thickness.</li>
<li>Calculate the extrusion multiplier using the following formula: <strong>Extrusion multiplier = (Extrusion width (0.45) / Average measured wall thickness)</strong>.</li>
<li>Adjust the Extrusion Multiplier in Filament Settings → Filament</li>
<li>Re-print the cube with new settings and go back to step 3 if necessary.</li>
</ol>
<p><img decoding="async" style="max-height: 220px; display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusuki/prusuki-images/micrometer-small-jpg.JPG" height="400" data-hd-height="220px"></p>
<div class="warning-callout">Please note that cheap digital calipers may not be accurate enough to make reliable measurements of a single perimeter wall.</div>
<h4>Visual Method</h4>
<p>This method does not require any tools, only your sight. The point is to make sure your top layers are <strong>smooth</strong>, <strong>shiny,</strong> and without <strong>scarring or filament buildup</strong> near the perimeters.</p>
<p><img decoding="async" loading="lazy" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/destiky6.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-600x374.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-800x499.jpg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-300x187.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-768x479.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-1536x958.jpg 1536w" alt="" width="641" height="400"></p>
<ol>
<li>Download the <a href="https://cdn.help.prusa3d.com/wp-content/uploads/2021/04/visual-method-cube.zip">Visual Method Cube.stl</a></li>
<li>Slice it using the default Prusa PLA presets at 0.20mm layer height and print it.</li>
<li>Inspect the top layer of your cube visually and with the tip of the finger.</li>
<li>If the top is under extruded or not smooth, then re-adjust the Extrusion Multiplier accordingly by 1-2%.</li>
<li>Repeat the steps above as long as needed.</li>
</ol>
<p>If there is&nbsp;<strong>too much material</strong>&nbsp;near the perimeters,&nbsp;<strong>decrease</strong>&nbsp;the Extrusion Multiplier value.</p>
<p><img decoding="async" style="max-height: 390px; margin-left: auto; margin-right: auto; display: block;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusuki/prusuki-images/buildu.jpg" data-hd-height="390px" data-hd-align="left"></p>
<p>If there are&nbsp;<strong>visible gaps</strong>&nbsp;between layer lines,&nbsp;<strong>increase</strong> the Extrusion Multiplier value. (Microscopic gaps near the perimeters are OK.)</p>
<p><img decoding="async" style="max-height: 430px; margin-left: auto; margin-right: auto; display: block;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusuki/prusuki-images/gaps.jpg" data-hd-height="430px" data-hd-align="left"></p>


Extrusion multiplier calibration

<p>Stringing or oozing, also known as "hairy prints", is the name given for when small strings of filament are left on a printed model. This usually happens when the filament keeps flowing from the nozzle while the extruder is moving to another object. You can see this as a marginal line of filament left between the objects.</p>
<p>This issue is caused by <strong>very high printing temperatures and/or using incorrect retraction settings</strong>. This can be solved by changing a couple of settings in PrusaSlicer and checking your hardware.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8442%;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/90014ff5fc80d10b.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/90014ff5fc80d10b-600x383.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/90014ff5fc80d10b-800x511.jpg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/90014ff5fc80d10b-300x192.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/90014ff5fc80d10b-768x490.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/90014ff5fc80d10b-1536x981.jpg 1536w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/90014ff5fc80d10b-2048x1308.jpg 2048w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/90014ff5fc80d10b.jpg 1600w" alt="" width="400" height="255"></td>
<td style="width: 48.8442%;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/b1b72c32290b8c00.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/b1b72c32290b8c00-600x400.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/b1b72c32290b8c00-800x534.jpg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/b1b72c32290b8c00-300x200.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/b1b72c32290b8c00-768x512.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/b1b72c32290b8c00.jpg 1600w" alt="" width="400" height="267"></td>
</tr>
</tbody>
</table>
<h3>Stringing from material left on the nozzle</h3>
<p>If you print for a long time from a single type of filament, such as PET-G, the filament can create a thin layer in the nozzle. This can cause stringing as the strands of the filament stick to the surface of the print. Therefore, thoroughly clean the nozzle before printing and make sure that any dirt or remnants of previous filaments are removed from the nozzle.</p>
<div class="warning-callout">We highly recommend using our official (factory default) preset settings in PrusaSlicer. However, if you are printing with your own settings, make sure that you have the retraction settings configured correctly.</div>
<h3>PrusaSlicer settings</h3>
<p><img decoding="async" loading="lazy" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/432d664dd4b64d78_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/432d664dd4b64d78_painted-600x359.jpeg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/432d664dd4b64d78_painted-800x479.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/432d664dd4b64d78_painted-300x179.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/432d664dd4b64d78_painted-768x459.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/432d664dd4b64d78_painted-1536x919.jpeg 1536w, https://cdn.help.prusa3d.com/wp-content/uploads/2022/02/432d664dd4b64d78_painted.jpeg 1600w" alt="" width="700" height="419"></p>
<p>You should start by checking a parameter known as Retraction. What does retraction do? When the extruder has finished printing one section/object of your g-code, the filament is pulled back into the nozzle. Once the extruder moves to the next location the printing process continues – the filament is pushed back out and it starts extruding from the nozzle again. Retraction settings can be found in PrusaSlicer in <em>Printer Settings -&gt; Extruder 1</em>.</p>
<p>Flexible filaments usually need longer retractions, because the material stretches while being pulled back to the nozzle. Flexible materials are a special case and can need a lot of tweaking and tuning.</p>
<p><strong>The retraction settings are:</strong></p>
<ul>
<li><strong>Retraction length:</strong> Amount that the filament is pulled back when a retraction is triggered. <strong>On the MK2.5/S and MK3/S/+, the retraction length should be a maximum of 2 mm.</strong></li>
</ul>
<div class="tip-callout">Due to the Bowden extruder, the retraction length of the Original Prusa MINI/MINI+ presets are much longer (default 3.2 mm).</div>
<ul>
<li><strong>Lift z:</strong> lifts the extruder during movement. Having this setting lower will improve stringing. Note that disabling this feature may cause the nozzle to hit the printed part.<strong><br /></strong></li>
<li><strong>Retraction Speed:</strong> Extruder motor speed on retraction. A higher value improves stringing, but if it is too high it may skip steps in the motor.</li>
<li><strong>Minimum travel after retraction:</strong> Amount of move that will trigger a retraction (mm). The preset number in PrusaSlicer is 1 mm, which is a low amount. Having this number higher will get lower printing times, but increase oozing and stringing.</li>
<li><strong>Retract on layer change:</strong> Activates retraction when the layer changes to the next one. It is recommended to leave this option on.</li>
<li><strong>Wipe while retracting:</strong> Moves the nozzle (wipe) while the retraction is happening. It is recommended to leave this option on.</li>
<li><strong>Retract amount before wiping:</strong> This option does a quick retract before doing the wiping movement. More suitable for the Original Prusa MINI/MINI+.</li>
</ul>
<p><strong>Other settings that affect retraction:</strong></p>
<ul>
<li><strong>Only retract when crossing perimeters:</strong> <em>(Print settings -&gt; Infill -&gt; Advanced):</em> Disables retraction when the travel path does not exceed the upper layer's perimeter. Any oozing that happens will be within the walls and should be invisible.</li>
<li><strong>Avoid crossing perimeters:</strong> <em>(Print settings -&gt; Layers and perimeters -&gt; Quality):</em> Optimize travel moves in order to minimize the crossing of perimeters. This will lower the stringing amount, especially in the MINI/MINI+.</li>
<li><strong><a href="http://help.prusa3d.com/article/sequential-printing_124589">Sequential printing</a>:</strong> <em>(Print settings -&gt; Output options -&gt; Sequential printing):</em> Printing each object individually has a smaller chance of causing stringing between the parts. When using this feature, PrusaSlicer will warn you of any possibility of the extruder colliding with an already printed part, but follow the print closely.</li>
<li><strong>Nozzle temperature:</strong> <em>(Filament settings -&gt; Filament -&gt; Nozzle):</em> Lowering the temperature decreases the occurrence of strings. Try decreasing the nozzle temperature by 5 – 10°C and check whether there’s less stringing.</li>
</ul>
<h3>Filament</h3>
<p>Try using a different spool than the one that is causing the stringing. The filament might have gathered moisture, which will cause a lot of stringing.</p>
<h3>Hotend</h3>
<p>Stringing in the nozzle might be caused by a heat dissipation issue in the nozzle. Try <a href="http://help.prusa3d.com/guide/how-to-replace-a-heatbreak-heatsink-heaterblock-mk3s-mk3s-mk2-5s-mmu2s_16104">re-applying thermal paste</a> on the threads between the heatbreak and the heatsink.</p>
<p>If you have recently changed any component in the hotend, it is also possible that some individual parts are not in place. Go over the assembly of the hotend and check for any parts that may be different from the <a href="http://help.prusa3d.com/guide/how-to-replace-a-heatbreak-heatsink-heaterblock-mk3s-mk3s-mk2-5s-mmu2s_16104">instructions</a>.</p>
<h3>Enough settings, pass me my <strong>heat-gun!</strong></h3>
<p>If you don’t feel like tweaking any of the settings, well, then there is an alternative. You can get rid of the strings with a heat gun (or often with a lighter – but be very careful). Set your heat-gun to around 200 °C and aim at the strings for one or two seconds. This will melt the strings, and the printed object should remain undamaged. Do not leave the heat source on the printed model for longer than one or two seconds, as this may deform the part.</p>


Stringing and oozing

<div><strong><img decoding="async" loading="lazy" style="float: right;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-768x768.jpg 768w" alt="" width="225" height="225"></strong></div>
<h3>Basic info</h3>
<div><strong>PETG</strong> is one of the most easily printable materials, it is <strong>inexpensive and suitable for beginners</strong>. Relatively high tenacity and temperature resistance make it <strong>suitable for printing technical parts</strong> (for example parts of our printers).</div>
<div>&nbsp;</div>
<div><strong>Recommended nozzle temperature:</strong> 230 °C for the first layer, 240 °C for the other layers</div>
<div>&nbsp;</div>
<div><strong>Recommended bed temperature:</strong> 85 °C for the first layer, 90 °C for the other layers</div>
<div>&nbsp;</div>
<div><strong>Heatbed:</strong> Using powder-coated TXT or satin sheet is highly recommended. Printing on smooth PEI surface might damage the sheet.</div>
<h3>Description</h3>
<div>
<p><a href="https://www.prusa3d.com/category/prusament-petg/"><strong data-stringify-type="bold">PETG</strong></a> (Polyethylene Terephthalate modified with Glycol) is a commonly used technical material, popular among 3D printer users for its <strong>low price and good printability</strong>. It’s tenacious, with good temperature resistance; PETG is most commonly used for printing various mechanical parts, holders, clamps, and waterproof parts (thanks to great layer adhesion).</p>
<p>PETG has a glossy surface, adheres greatly to a print sheet, and <strong>does not shrink or warp</strong> (it has very little thermal expansion), therefore it’s suitable for printing large models. Plus, its high tenacity and flexibility often <strong>prevent it from breaking.</strong> Due to good temperature resistance, PETG parts are suitable both for interior and most exterior use (with temperatures below 80 °C). <strong>Parts of our printers are made of PETG!</strong></p>
<p>The letter G in PETG means that it’s modified with glycol during the manufacturing process. Glycol makes PET less brittle, easier to print, and more transparent for translucent prints. Of course, you can print also with PET filaments without glycol. However, printing with only PET is challenging and does not offer any advantage whatsoever.</p>
<div class="warning-callout">Even though PETG in itself may be considered <a href="http://help.prusa3d.com/article/food-safe-fdm-printing_112313">food-safe</a>, it consists of layers, as every 3D print, in which bacteria can grow over time. You can prevent this by applying a <strong>food-safe(epoxy) coating.</strong> Also, a stainless-steel nozzle should be used for if food is the intended application.</div>
<p>Although <strong>PETG</strong> is frequently used in <strong>food industry</strong> and is considered <strong>food-safe</strong>, we do not recommend it (or any other filament) for printing dishes or other stuff that comes into direct contact with food. The main reason is tiny print layer surface grooves that can support numerous bacterial colonies. But if you still want 3D printed dishes, we suggest <strong>applying a special layer</strong> that seals the surface (food-safe coating) and printing with a clean steel nozzle.</p>
<p>Some of the manufacturers <strong>enrich PETG with various additives</strong> and sell these materials under different names. For example, Spoolworks EDGE by E3D is modified PET/Copolyester Blend with additives. The goal is to acquire better visual qualities, surface and layer adhesion, etc.</p>
<p>To compare supported material properties, see our <a href="https://help.prusa3d.com/en/materials">material table.</a></p>
</div>
<table class="striped">
<tbody>
<tr>
<th>
<p>Pros</p>
</th>
<th>
<p>Cons</p>
</th>
</tr>
<tr>
<td>
<p>✔ Easy to print</p>
</td>
<td>
<p>✖ Possibility of stringing</p>
</td>
</tr>
<tr>
<td>
<p>✔ Good layer adhesion</p>
</td>
<td>
<p>✖ Poor bridging and overhangs</p>
</td>
</tr>
<tr>
<td>
<p>✔ Tough and durable</p>
</td>
<td>
<p>✖ Not great for printing detailed parts</p>
</td>
</tr>
<tr>
<td>
<p>✔ Low warping</p>
</td>
<td>
<p>✖ Bonds strongly to the print surface</p>
</td>
</tr>
<tr>
<td>✔ High temperature-resistance</td>
<td>
<p>✖ Soluble in dangerous chemicals</p>
</td>
</tr>
<tr>
<td>✔ Water and humidity resistant</td>
<td>
<p>✖ Supports are hard to remove</p>
</td>
</tr>
</tbody>
</table>
<h3>Best use</h3>
<p>PETG is used universally but is especially suitable for mechanical parts for both indoor and outdoor use. We use PETG to print parts for our printers! Plastic bottles are also made from this kind of material.</p>
<h3>Tips for successful printing</h3>
<p><strong>Temperature settings and cooling</strong></p>
<p>Unlike PLA, <strong>PETG requires a heated bed (85 °C).</strong> Its bridging- and overhang-behavior is usually worse, plus it is prone to stringing. Stringing can be moderated with higher retractions and lower nozzle temperature, but we suggest <strong>using the PrusaSlicer profiles that should work fine.</strong> It’s important to <strong>cool the PETG print</strong> - this helps to keep the model detailed and prevents stringing and oozing. But if you want the model to be as tough as possible, try to turn off the print fan. Higher filament temperature improves merging between layers which leads to better mechanical resistance. Otherwise, we recommend printing the first few layers with the print fan off to prevent deformation, then with the fan running at half its power.</p>
<div class="warning-callout"><strong>Do not print on the smooth PEI sheet</strong> as the adhesion may be too strong!</div>
<p><strong>Print surface preparation</strong></p>
<p>Make sure the print surface is clean, as described in <a href="http://help.prusa3d.com/article/first-layer-issues_1804">our dedicated article</a>. It is advisable to use one of the <strong>powder-coated print sheets. Do not print on the smooth PEI sheet</strong> as the adhesion may be too strong! If you decide to use the smooth PEI sheet anyway, apply a glue stick on it before printing.</p>
<p><strong>Adding more perimeters for more solid parts</strong></p>
<p>If you want to print truly solid parts, <strong>try to increase the number of perimeters</strong> instead of adding more infill.</p>
<h3>Postprocessing</h3>
<p>PETG can be easily sanded both dry and wet.</p>
<p><strong>Dissolving PETG</strong></p>
<p><strong>Dissolving and smoothing PETG</strong> is possible only in a laboratory by skilled lab workers using <strong>dangerous chemicals</strong> (Dichloromethane).</p>
<h3>Sample prints</h3>
<table style="border-collapse: collapse; width: 100%; height: 954px;" border="0">
<tbody>
<tr style="height: 300px;">
<td style="width: 48.805%; height: 300px;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-768x768.jpg 768w" alt="" width="800" height="800"></td>
<td style="width: 48.805%; height: 300px;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-768x768.jpg 768w" alt="" width="800" height="800"></td>
</tr>
<tr style="height: 18px;">
<td style="width: 48.805%; height: 18px; text-align: center;"><em>MMU (Multi-Material Unit)</em></td>
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Electronics cover and other printer parts</em></td>
</tr>
<tr style="height: 300px;">
<td style="width: 48.805%; height: 300px;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-768x768.jpg 768w" alt="" width="800" height="800"></td>
<td style="width: 48.805%; height: 300px;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-768x768.jpg 768w" alt="" width="800" height="800"></td>
</tr>
<tr style="height: 18px;">
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Ukulele</em></td>
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Various mechanical parts</em></td>
</tr>
<tr style="height: 300px;">
<td style="width: 48.805%; height: 300px; text-align: center;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-768x768.jpg 768w" alt="" width="800" height="800"></td>
<td style="width: 48.805%; height: 300px; text-align: center;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-768x768.jpg 768w" alt="" width="800" height="800"></td>
</tr>
<tr style="height: 18px;">
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Electronic parts</em></td>
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Boxes and organizers</em></td>
</tr>
</tbody>
</table>


PETG

Original Prusa i3 MK3/MK3S/MK3S+ to MK4S/MK3.9S upgrade

Original Prusa MK4/MK3.9 to MK4S/MK3.9S upgrade

Assembly manuals

Basic calibration

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What to do when the printer reports an error message during calibration.

Calibration Error Messages

All information you need to know to learn how to calibrate your 3D printer to achieve perfect prints.

Calibration

Printer description

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General Information

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About your printer

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Material guide

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In this section, you can find material guides, printer troubleshooting and general info about using your printer.

Using the printer

Print Quality Troubleshooting

QR Error codes

Printer troubleshooting

Print Error Messages

Description of how to recognize and solve common problems, especially hardware and electronics related.

Troubleshooting

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Learn about different nozzles, Raspberry Pi connection, Octoprint and more.

3rd party accessories & Other projects

About PrusaSlicer

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Top toolbar

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Printer settings

Advanced features

The official documentation for the PrusaSlicer slicing software. From basic configuration to advanced settings like modifier meshes.

PrusaSlicer

1. Introduction

1a. Parts check

2. Upgrading the Y-axis

3. Upgrading the xLCD

1b. Printer disassembly

4. Upgrading the Nextruder

1c. Parts preparation

2. Frame assembly

4B. Upgrading the Nextruder (MMU3)

3. X-axis & X-carriage assembly

5. Upgrading the connectivity

6. Preflight check

4. Z-axis assembly

Manual changelog

5. Nextruder assembly

6. xLCD assembly

7. Y-carriage & Heatbed assembly

8. Preflight check

Prusa Connect &amp; PrusaLink

<h3>What happened? </h3>
<p>During the configuration of <strong>Prusa Connect</strong> on the <strong>Original Prusa MINI/+</strong>, <strong>MK4/S</strong>, <strong>MK3.9/S, MK3.5/S</strong> or <strong>XL</strong> an error on this configuration can occur and the printer shows the message "<strong>Registration to Prusa Connect failed due to: ~</strong>". In place of <strong>~</strong>, a text with more details is shown, from the list below. Depending on the specific shown text, there are different causes and fixes. </p>
<p>Error name: Connect Registration Failed</p>
<p>Error code: #12401 (MINI), #13401 (MK4), #26401 (MK4S), #21401 (MK3.9), #23401 (MK3.5), #17401 (XL)</p>
<h4>DNS error</h4>
<p>The printer wasn't able to resolve the <strong>hostname</strong> of the Prusa Connect server into an IP address. The hostname is a unique label assigned to a device connected to a network. </p>
<ul>
<li>The printer is not connected to the network at all.</li>
<li>In case of a <strong>static</strong> configuration (non-DHCP), the <strong>DNS server</strong> is not configured or configured incorrectly.</li>
<li>The local DNS server is currently not working.</li>
<li>The Connect hostname is reconfigured to some that doesn't exist. For example, this can occur if loading a .ini file with an invalid configuration.</li>
</ul>
<h4>Refused</h4>
<p>It's not possible to reach the server on the network level, hence it is not possible to establish a TCP connection. The system is either not answering at all or actively refuses the connection. </p>
<ul>
<li>The internet connection is not working, or a firewall blocks the communication.</li>
<li>In the case of a <strong>static</strong> configuration (non-DHCP), the <strong>gateway </strong>(typically, this is the IP address of the router) is not configured or configured incorrectly. </li>
<li>The Connect server is under maintenance. </li>
<li>Too many TCP connections are open with the printer, for example in PrusaLink. </li>
</ul>
<h4>TLS error</h4>
<p>This message points to an error doing a <strong>SSL/TLS handshake</strong>. This handshake is the process to create a safe and encrypted connection. </p>
<ul>
<li>Time is not synchronized on the printer (MINI/+). The time synchronization occurs for each internet connection, through the <a href="http://help.prusa3d.com/article/ntp-server-mini_151132">NTP server</a>. It is possible this might take more time than initially expected, or rarely, that there might be issues with the server. </li>
<li>A restrictive firewall (for example but not limited to a corporate proxy firewall) may restrict an automatic access to the NTP server. In that case, it will be necessary to manually allow the printer to access the NTP server.</li>
<li>Something in the path is trying to tamper with the communication, for example but not limited to an attack. </li>
</ul>
<h4>Unauthorized</h4>
<p>The server claims that the printer is not authorized. The printer is not recognized as an Original Prusa. </p>
<h4>Server error</h4>
<p>The server is returning a <strong>500 Internal Server Error</strong> or similar. The issue is on the Connect side, and is expected to be fixed on its own. </p>
<h4>Internal error</h4>
<p>This error is caused by an issue related to the printer firmware. </p>
<h4>Network error</h4>
<p>Similar to the Refused error, but the connection dropped after it was initialized. </p>
<ul>
<li>Glitchy internet connection.</li>
<li>The <strong>latency</strong> to the Connect servers is too high. A geographic location is very far from our Connect servers can contribute to this cause.</li>
<li>The Connect server is temporarily down.</li>
</ul>
<h4>Protocol error</h4>
<p>The response from the server is not recognized.</p>
<ul>
<li>Bug on the server side. This cause is on our side and expected to be fixed on its own. </li>
<li>Too old firmware on the printer and it's no longer supported.</li>
<li>A misconfiguration from the <strong>.ini file</strong> loaded on the printer, connecting to something different than our Connect server.</li>
</ul>
<h3>How to fix it? </h3>
<h4>DNS error, Refused</h4>
<p>Ensure that the printer is connected to the internet. In case of a static (non-DHCP) connection, ensure the correct settings are there, or test a DHCP connection. Also, check the .ini configuration file, and in case, rewrite the file. </p>
<p>If the previous steps didn't fix the issue, attempt a <a href="http://help.prusa3d.com/article/factory-reset-mini_177516">factory reset</a>. </p>
<h4>TLS error</h4>
<p>Reattempt the Connect registration, after the printer is connected to the internet for a few more minutes. </p>
<p>If the previous step didn't fix the issue, double-check your network <strong>firewall</strong>. Some firewalls will need for the NTP server to be allowed manually. The specific steps will depend on your specific firewall, we recommend checking your firewall documentation. </p>
<h4>Unauthorized</h4>
<p>If your printer is not an Original Prusa printer, it cannot use our Prusa Connect service.</p>
<p>In case your printer is an Original Prusa, <a href="http://help.prusa3d.com/article/firmware-updating-mini-mini_124784"> re-flash or update its firmware</a>. </p>
<h4>Server error</h4>
<p>A server error indicates an issue from our side. The issue will be fixed on its own, try registering again to Prusa Connect later. </p>
<h4>Internal error</h4>
<p><a href="http://help.prusa3d.com/article/firmware-updating-mini-mini_124784">Re-flash or update the printer firmware</a>. If this does not solve the issue, take note if the printer might have other issues, even if not directly related. </p>
<h4>Network error</h4>
<p>Ensure that your internet connection is stable and not glitchy. To confirm whether an inconsistent internet connection caused the issue, test another connection, if available, such as a hotspot from your mobile phone. </p>
<h4>Protocol error</h4>
<p>Ensure that the printer is running our latest firmware version. If it is running an old version, update the firmware. Also, check the .ini configuration file, and in case, rewrite the file.</p>


Connect Registration Failed

<p>The Prusa CORE One, and the Original Prusa XL, MK4/S, MK3.9/S are equipped with a <a href="http://help.prusa3d.com/article/loadcell-mk4-s-mk3-9-s-xl_401253">loadcell</a>. Thanks to this component, starting from firmware 6.0.0, the printer can detect whether the filament is stuck and not moving, for example when the nozzle is clogged. </p>
<p>If this is detected, the print pauses and the printer shows the message: "<strong>Stuck filament detected. The filament seems to be stuck. Please unload it from the extruder and load it again</strong>." </p>
<p>Once the <strong>unload </strong>button is pressed, the printer unloads the filament. After this, it prompts filament loading and resumes the print. </p>
<div class="tip-callout">It is important to note that detecting stuck filament is possible only inside the Nextruder, as pressure builds up from the nozzle to the upper part of the Nextruder. However, if your filament is tangled on the spool, there will be no internal pressure, just outside tension, which the loadcell won't recognize.</div>
<div>Stuck filament detection won't be possible on MK3.5 and MINI/MINI+ as they aren't equipped with the loadcell sensor.</div>
<p style="text-align: center;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/04/e884e31f8ae9e52017bacbeb8fcd544e.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Stuck filament detection #13101 (MK4) #21101 (MK3.9)" alt="" width="500" height="333" loading="lazy" /><em>Screenshot from the Original Prusa MK4</em></p>


Stuck filament detection #31101 (CORE One) #26101 (MK4S) #13101 (MK4) #27101 (MK3.9S) #21101 (MK3.9) #17108 (XL)

<h3>What happened?</h3>
<p>The printer is showing the message "<strong>Hotend preheat error: Check the print head heater and thermistor wiring for potential damage</strong>"</p>
<p>Error name: Hotend preheat error</p>
<p>Error code: #26201 (MK4S) #13201 (MK4)  # 27201 (MK3.9S) #21201 (MK3.9) #31201 (CORE One)</p>
<p>This error is shown when the printer can't heat the nozzle more than <strong>2 ºC for 20 seconds</strong>. The printer starts a safety feature that instantly stops the heating process and displays the message on the screen. The printer then waits for the user to inspect all parts and if needed fix the issue.</p>
<h3>How to fix it?</h3>
<p>Make sure that the <strong>ambient temperature</strong> where the printer is is stable, and above <strong>10 ºC</strong>.</p>
<h4>Extruder inspection</h4>
<p>This error can be caused by any damage to the <strong>hotend heater</strong> or the <strong>hotend thermistor</strong>.</p>
<p>Access the LoveBoard and check the <span style="color: #843fa1;"><strong>heater</strong> </span>and <strong><span style="color: #236fa1;">thermistor</span></strong> cables. Make sure that they are connected correctly and that there is no damage along their length.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/4d8068ede1cb7f665960fe46fa065702.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Hotend preheat error #13202 (MK4)" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/b1fcbf1f9cc8f479_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Preheat error #13202 (FIONA)" alt="" width="400" /></td>
</tr>
</tbody>
</table>
<h4>xBuddy board inspection</h4>
<p>On the main board check if the <a href="http://help.prusa3d.com/article/blown-fuse-mk4-s-mk3-9-s_411666">fuse that protects the extruder</a> is not damaged.</p>
<p>Make sure that the Loveboard main cable is correctly connected to the xBuddy board.</p>
<h4>Multimeter check</h4>
<p>If you have a multimeter available, use <a href="http://help.prusa3d.com/article/multimeter-usage_2117">this guide</a> to check the resistance on the hotend heater and the hotend thermistor.</p>


Hotend preheat error #26201 (MK4S) #13201 (MK4)  # 27201 (MK3.9S) #21201 (MK3.9) #31201 (CORE One)

<h3>What happened?</h3>
<p>The printer is showing the message <strong>"Check the heatbed heater &amp; thermistor wiring for possible damage."</strong></p>
<p>Error name: Bed preheat error</p>
<p>Error code: #26201 (MK4S) #13201 (MK4)  # 27201 (MK3.9S) #21201 (MK3.9) #28201 (MK3.5S) #23201 (MK3.5) #31201 (CORE One)</p>
<p>This message is shown when, during the preheat, the printer does not increase more than <strong>2 ºC for 20 seconds</strong>. The heating is paused so the issue can be fixed.</p>
<h3>How to fix it?</h3>
<p>Make sure that the <strong>ambient temperature</strong> where the printer is is stable, and above <strong>10 ºC</strong>.</p>
<p>This error can be caused by damage to either the <strong>heatbed thermistor</strong> or the <strong>heatbed power cable</strong>.</p>
<div class="tip-callout">Doing <strong>regular maintenance</strong> on the printer may prevent this type of issue.</div>
<p>On the heatbed, check the following:</p>
<ul>
<li>See if the <strong>thermistor </strong>is firmly seated below the <strong>Golden Kapton tape.</strong></li>
<li>Make sure that the <strong>washer </strong>is screwed above the round cable connector, not below it.</li>
<li>Check if the <strong>M3nN nut</strong> is holding the screw firmly.</li>
<li>Access the xBuddy board. Check the <strong><span style="color: #236fa1;">heatbed power cable</span></strong>, the <strong><span style="color: #2dc26b;">heatbed thermistor</span></strong>, and the <a href="http://help.prusa3d.com/article/blown-fuse-mk4-s-mk3-9-s_411666">fuse that protects the heatbed</a>.</li>
</ul>
<table style="border-collapse: collapse; width: 100%; height: 322.875px;" border="0">
<tbody>
<tr style="height: 301.875px;">
<td style="width: 48.8358%; height: 301.875px;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/Heatbedthermistor.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Preheat error #13201 (FIONA)" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8358%; height: 301.875px;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/b219085ec996c508.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Preheat error #13201 (FIONA)" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
<tr style="height: 21px;">
<td style="width: 48.8358%; height: 21px;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/30e875e9b027e87d.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Preheat error #13201 (FIONA)" alt="" width="400" height="1200" loading="lazy" /></td>
<td style="width: 48.8358%; height: 21px;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/77686da340e7e4a3_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Preheat error #13201 (FIONA)" alt="" width="400" /></td>
</tr>
</tbody>
</table>
<p>In case all the items are correct, there might be an internal break in one of the cables. If you do not have a multimeter, it is possible to check the cables using the following test: </p>
<ol>
<li>Use a hairdryer to blow hot air at the heatbed.</li>
<li>While doing that, check if there is any temperature change on the LCD screen.</li>
<li>If there is a positive temperature change it means that the heatbed thermistor is working. In this case, the heater is defective.</li>
<li>If there is no change at all, the heatbed thermistor is defective.</li>
</ol>
<h4>Multimeter check</h4>
<p>In case you have a multimeter available, it is possible to check the resistance of the cables using the <a href="http://help.prusa3d.com/article/multimeter-usage_2117">Multimeter usage</a> guide.</p>


Bed preheat error #26201 (MK4S) #13201 (MK4)  # 27201 (MK3.9S) #21201 (MK3.9) #28201 (MK3.5S) #23201 (MK3.5) #31201 (CORE One)

<p>This is an advanced system for displaying error screens, providing more useful information to the user. In case of an issue, the printer will display the name of the error followed by a brief description and a QR code. Take your phone, scan the code, and you will be immediately redirected to an article that will explain in detail what happened to your printer and how to fix the problem.</p>
<p>You can see the printers that show the QR code in our <a href="https://github.com/prusa3d/Prusa-Error-Codes">GitHub page</a>. Note that older firmware versions may have different looks.</p>
<table style="border-collapse: collapse; width: 100%; border-style: none;" border="0">
<tbody>
<tr>
<td style="width: 32.1716%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/09/a8eb010a2d9a57fbc9c69b36b0477893.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="QR Error codes REVIEW" alt="" width="225" height="300" loading="lazy" /></td>
<td style="width: 67.8023%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/09/b7e7fce178235ca5a553c4ff07e83c65.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="QR Error codes REVIEW" alt="" width="500" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h3>How to use the error code</h3>
<div>
<p>In case your printer displays the error screen, there are multiple ways to access the article:</p>
<ul>
<li>Scan the QR code from the printer screen using a phone or tablet</li>
<li>Use the link displayed on the screen (e.g. help.prusa3d.com/en/12201)</li>
<li>Open help.prusa3d.com and search for the error (e.g. 12201)</li>
</ul>
<p>Follow the article explaining what went wrong and how to fix the issue. Note that some errors might require you to replace broken part(s) of the printer. If a replacement is necessary, there will be a link to the service guide at the bottom of the article.</p>
<h3>Error code explained</h3>
<p>How is each code created? Let's use error #12201 again as an example. The code consists of five numbers with the following pattern: XXYZZ</p>
<table class="striped">
<tbody>
<tr style="height: 18.4px;">
<td style="width: 48.8442%; text-align: center; height: 18.4px;"><strong># XXYZZ</strong></td>
<td style="width: 48.8442%; text-align: center; height: 18.4px;"><strong><a href="http://help.prusa3d.com/article/preheat-error-bed-12201-mini_112444">Heating failed bed #12201 (MINI)</a></strong></td>
</tr>
<tr style="height: 119.2px;">
<td style="width: 48.8442%; height: 119.2px;">
<p>XX - ID number of the printer, according to USB PID</p>
<p>Y - Error category (common for all printers)</p>
<p>ZZ - ID number for the specific error</p>
</td>
<td style="width: 48.8442%; height: 119.2px;">
<p>12 - Printer number 12: Original Prusa MINI</p>
<p>2 - Error category: Temperature error</p>
<p>01 - Specific error code: Heatbed heating failed</p>
</td>
</tr>
</tbody>
</table>
</div>
<div>
<h3>Device hash</h3>
<p>The URL link embedded in the QR code may contain an optional “device hash”. On the CORE One, MK4/S, MK3.9/S, MK3.5/S, XL, MINI/+, this can be disabled in <em>Settings -&gt; System</em>, and on the SL1/S in <em>Settings -&gt; Settings and Sensors</em>. </p>
<p>Including this information enables us to check whether you are running the latest version of firmware, and if not, we will inform you at the top of the article. The information provided in the URL is stored in our database to help us better understand which errors are the most common and how many errors each printer experienced.</p>
</div>
<p>The device hash cannot be used to recover anything sensitive like a serial number and isn’t used for anything else than the QR codes feature therefore there are absolutely no security concerns. This feature is turned ON by default. In case you don't want to use this enhanced feature, you can switch it off in the printer's menu by setting the “Device hash in QR” to OFF.</p>
<p>Once you turn it off, the QR code URL will contain only the following: https://help.prusa3d.com/en/12201/</p>
<table class="striped">
<tbody>
<tr style="height: 18px;">
<td style="width: 30.8567%; height: 18px;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/MINI_device_hash_toggle_upscaled.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/MINI_device_hash_toggle_upscaled-300x400.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/MINI_device_hash_toggle_upscaled-450x600.jpg 450w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/MINI_device_hash_toggle_upscaled-225x300.jpg 225w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/MINI_device_hash_toggle_upscaled-768x1024.jpg 768w" alt="" width="250" height="333" loading="lazy" /></td>
<td style="width: 66.8317%; height: 18px;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/SL1-Setting-and-sensors.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/SL1-Setting-and-sensors-600x360.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/SL1-Setting-and-sensors-800x480.jpg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/SL1-Setting-and-sensors-300x180.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/03/SL1-Setting-and-sensors-768x461.jpg 768w" alt="" width="600" height="360" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p style="text-align: center;"><em>Device hash toggle for MINI on the left and SL1 on the right.</em></p>


<h3>What happened?</h3>
<p>The printer is showing the message <strong>"Check the print head thermistor wiring for possible damage."</strong></p>
<p>Error name: Hotend mintemp error</p>
<p>Error code: #26208 (MK4S) #13208 (MK4) #27208 (MK3.9S) #21208 (MK3.9)</p>
<p>This error is shown when the printer's nozzle temperature drops below <strong>5 ºC</strong> at any point. If this happens during a print, the print will be stopped.</p>
<h3>How to fix it?</h3>
<h4>Extruder inspection</h4>
<p>This error is usually caused by the <strong>hotend thermistor</strong>. </p>
<p>Access the LoveBoard. Check if the thermistor is connected correctly and if there is no damage along the cable length.</p>
<p>If you have a multimeter, it is possible to check the resistance of the cables to verify if they are damaged. For that, use our <a href="http://help.prusa3d.com/article/multimeter-usage_2117">Multimeter usage</a> guide.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/4d8068ede1cb7f665960fe46fa065702.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Hotend mintemp error #13208 (MK4)" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/b1fcbf1f9cc8f479_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Maxtemp error #13206 (FIONA)" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4>xBuddy board inspection</h4>
<p>Make sure that the Loveboard main cable is correctly connected to the <strong>xBuddy board</strong>.</p>


Hotend mintemp error #26201 (MK4S) #13201 (MK4)  # 27201 (MK3.9S) #21201 (MK3.9) #31201 (CORE One)

<h3>What happened?</h3>
<p>The printer is showing the error "<strong>Hotend thermal runaway: Check the print head thermistor wiring for potential damage</strong>".</p>
<p>Error name: Hotend thermal runaway </p>
<p>Error code: #31201 (CORE One) #26201 (MK4S) #13201 (MK4) #27201 (MK3.9S) #21201 (MK3.9) </p>
<p>The error will show if the temperature on the nozzle drops by <strong>12 ºC</strong> for an extended period of time. This temperature drop would usually not be an issue, but if the heat is not recovered after <strong>60 seconds</strong> the error will happen. In this case, the printer will stop the heating and display the message on the screen.</p>
<h3>How to fix it? </h3>
<p>Make sure that the <strong>ambient temperature</strong> where the printer is is stable, and above <strong>10 ºC</strong>.</p>
<h4>Extruder inspection</h4>
<p>This error can be caused by any damage to the<strong> hotend heater</strong> or the <strong>hotend thermistor</strong>.</p>
<p>Make sure that the hotend thermistor is inserted in the heater block.</p>
<p>Access the LoveBoard. Check if the heater and the thermistor are connected correctly and if there is no damage along their length.</p>
<p>If you have a multimeter, you can use our <a href="http://help.prusa3d.com/article/multimeter-usage_2117">Multimeter usage</a> guide to check if the cables are damaged.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/4d8068ede1cb7f665960fe46fa065702.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Hotend thermal runaway #13204 (MK4)" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/b1fcbf1f9cc8f479_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Thermal runaway #13204 (FIONA)" alt="" width="1600" height="1200" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4>xBuddy board inspection</h4>
<p>On the main board, check if the <a href="http://help.prusa3d.com/article/blown-fuse-mk4-s-mk3-9-s_411666"> fuse that protects the hotend</a> is not damaged.</p>
<p>Make sure that the Loveboard main cable is correctly connected to the xBuddy board.</p>


Hotend thermal runaway #31201 (CORE One) #26204 (MK4S) #13204 (MK4) #27204 (MK3.9S) #21204 (MK3.9)

<h3>What happened?</h3>
<p>The printer is showing the message <strong>"Check the heatbed thermistor wiring for possible damage."</strong></p>
<p>Error name: Bed thermal runaway </p>
<p>Error code: #26203 (MK4S) #13203 (MK4) #27203 (MK3.9S) #21203 (MK3.9) #28203 (MK3.5S) #23203 (MK3.5)</p>
<p><strong>Thermal Runaway</strong> is a safety feature designed to cut power to the heaters in case of a cable malfunction. If your printer's thermistor somehow dislodges itself, electronic parts can get a lower (incorrect) temperature reading. In an attempt to compensate for the lower temperature, the heater could reach dangerously high temperatures.</p>
<p>If the <strong>heatbed </strong>temperature drops by more than <strong>2 ºC</strong> for over<strong> 60 seconds</strong>, the printer will shut down the print and show the Thermal Runaway error.</p>
<h3>How to fix it?</h3>
<p>Make sure that the ambient temperature is above <strong>10 ºC</strong>, and that there are <strong>no sources of cooling</strong> near the printer, like air conditioning or windows.</p>
<p>Check if the thermistor is well secured under the <strong>golden Kapton tape</strong>.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/Heatbedthermistor.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Thermal runaway #13203 (FIONA)" alt="" width="600" height="450" loading="lazy" /></p>
<p>If you are printing small objects with high-temperature filaments, try to print multiple at once and/or place them away from the center of the heatbed.</p>
<p>Open the <strong>xBuddyBox-cover</strong> and the <strong>el-box-cover</strong> by opening the screws indicated below to access the heatbed cables. Make sure that the heatbed power cable did not slip from the screw, and that the heatbed thermistor cable is well connected.</p>
<p>If you have a multimeter, you can check the resistance of the cables using this guide: <a href="http://help.prusa3d.com/article/multimeter-usage_2117">Multimeter usage</a>.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/ef0adcc4ba6782d2_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Thermal runaway #13203 (FIONA)" alt="" width="400" height="267" loading="lazy" /></td>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/783109cb80ab5ceb_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Thermal runaway #13203 (FIONA)" alt="" width="400" height="267" loading="lazy" /></td>
</tr>
</tbody>
</table>


Bed thermal runaway #26203 (MK4S) #13203 (MK4) #27203 (MK3.9S) #21203 (MK3.9) #28203 (MK3.5S) #23203 (MK3.5)

<h3>What happened?</h3>
<p>The printer is showing  the message <strong>"Check the heatbed thermistor wiring for possible damage."</strong></p>
<p>Error name: Bed mintemp error </p>
<p>Error code: #26207 (MK4S) #13207 (MK4) #27207 (MK3.9S) #21207 (MK3.9) #28207 (MK3.5S) #23207 (MK3.5)</p>
<p>This error is shown when the heatbed temperature drops below <strong>5 ºC</strong> at any time. This error can also happen when the printer is idle and not heated.</p>
<h3>How to fix it?</h3>
<p>Make sure that the <strong>ambient temperature</strong> where the printer is is stable, and above <strong>10 ºC</strong>.</p>
<p>This error is usually caused by a damaged <strong>heatbed thermistor</strong>.</p>
<div class="tip-callout">Doing regular maintenance on the printer may prevent this type of issue.</div>
<p>Check if the thermistor is well secured under the <strong>golden Kapton tape</strong>.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/Heatbedthermistor.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Maxtemp error #13205 (FIONA)" alt="" width="500" height="375" loading="lazy" /></p>
<p>In order to test if the thermistor is damaged, go to the printer menu in <em>Settings -&gt; Temperature -&gt; Heatbed temperature</em>, and set it to <strong>80 ºC</strong>. Then, move the heatbed cables by hand and see if the temperature will fluctuate. If the temperature fluctuates more than <strong>5 ºC</strong>, from the set temperature, the thermistor needs to be replaced.</p>
<p>Open the <strong>xBuddyBox-cover</strong> and the <strong>el-box-cover</strong> by opening the screws indicated below to access the heatbed cable connectors. Make sure that the heatbed power cable did not slip from the screw, and that the heatbed thermistor cable is well connected.</p>
<p>If you have a <strong>multimeter</strong>, you can check the resistance of the cables using this guide: <a href="http://help.prusa3d.com/article/multimeter-usage_2117">Multimeter usage</a></p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/ef0adcc4ba6782d2_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Thermal runaway #13203 (FIONA)" alt="" width="400" height="267" loading="lazy" /></td>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/783109cb80ab5ceb_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Thermal runaway #13203 (FIONA)" alt="" width="400" height="267" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h3> </h3>


Bed mintemp error #26207 (MK4S) #13207 (MK4) #27207 (MK3.9S) #21207 (MK3.9) #28207 (MK3.5S) #23207 (MK3.5)

<h3>What happened?</h3>
<p>The <strong>Prusa CORE One</strong>, and the <strong>Original Prusa MK4/S</strong>, <strong>MK3.9/S</strong> are equipped with a <strong>loadcell</strong>, which detects whether the nozzle is close enough to the steel sheet for printing and prevents damage from the nozzle digging into the steel sheet. </p>
<p>The printer firmware expects a measurement sample from the loadcell to occur within a specified time. In case this does not happen, the printer will show the message <strong>"There was a timeout while waiting for measurement sample, please repeat the action."</strong></p>
<p>Error name: Loadcell Timeout</p>
<p>Error code: #31528 (CORE One) #26528 (MK4S) #13528 (MK4) #27528 (MK3.9S) #21528 (MK3.9)</p>
<h3>How to fix it? </h3>
<h4>A visual inspection</h4>
<div class="warning-callout">Before you start, make sure:</p>
<ul>
<li>the filament is unloaded from the extruder</li>
<li>the printer is turned OFF and unplugged from electricity</li>
<li>the hotend and the heatbed are cooled down to ambient temperature</li>
</ul>
</div>
<p>Access the right side of the LoveBoard, where the loadcell cable is connected. To remove the side LoveBoard cover, on CORE One loosen two<span style="color: #000000;"> <span style="color: #236fa1;"><strong>M3x6 bolts</strong></span></span>, on MK4/S and MK3.9/S loosen one <span style="color: #843fa1;"><strong>M3x10 bolt</strong></span>. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/c565b5d3a12f4e32b712cc273759d4e8_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Timeout REVIEW #31528 (CORE One) #26528 (MK4S) #13528 (MK4) #27528 (MK3.9S) #21528 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/94e576c7396585eb388df6fd136a8ec8_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p>Once accessed, locate the <span style="color: #e67e23;"><strong>loadcell connector</strong></span> and cable, and check for any loose cable, disconnected cable, or visible damage. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;">
<p style="text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/98f9151af765084ab2be69a52d63f20c_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></p>
</td>
<td style="width: 48.8562%; text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/3c492d1b5efc9c403a26bd3c455c2ea7_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/5e54e7bdd6fef88f48746c4095106a4f.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="500" height="375" loading="lazy" /></h4>
<h4>Re-test the loadcell</h4>
<div class="warning-callout">Do not manipulate or touch the printer unless the instructions on the printer screen prompt you to do so.</div>
<div>
<p>Navigate to <em>LCD Menu -&gt; Control -&gt; Calibrations &amp; Tests -&gt; Loadcell Test</em> to initiate a loadcell test. </p>
<p>During the test, you will be asked to tap the nozzle at a specific time, and a progress bar shown on the screen is filled, depending on the pressure applied to the loadcell. If the bar is not filled or is filled irregularly, please contact our <a href="http://help.prusa3d.com/article/customer-support_2287">customer support</a>. </p>
<div class="tip-callout">Tapping of the nozzle can be done with a finger, as well as with a hard object. </div>
<table style="border-collapse: collapse; width: 100%; border-style: none;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/e03a4297a772916ed43b160f9300a4b6_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/3226ee7326e5f8c4057eb46f4d9f8a55_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h3>Loadcell white pad - visual check </h3>
<div class="warning-callout">Ensure to have the <strong>PG-assembly-adapter</strong> before continuing with the following procedure. If you do not have it, you can print it using the below files, depending on the printer you will use: <br /><a href="https://files.printables.com/media/prints/451501/stls/4104840_55cb7d05-d1f6-4cca-8159-db9ac9f62942/pg-assembly-adapter-mk4-r1.stl">PG-assembly-adapter printed with MK4/S</a><br /><a href="https://files.printables.com/media/prints/451501/stls/4240522_6fa05937-693e-4282-8dce-a98d3e93fd5f/pg-assembly-adapter-mk3-r2.stl">PG-assembly-adapter printed with MK3/S/+</a></div>
<ol>
<li>If any filament is loaded, unload the filament, then wait for the printer to fully cool down. After that, turn the printer off.</li>
<li>Remove the PG-case, together with the PG-ring, gearbox, and main plate. Remove all of these parts in one piece. </li>
</ol>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/1c7df54642bb103d2a7d3ed01b41cbff_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/67c593556671a61a79c52036477d3454.jpg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<ol start="3">
<li>The top part of the loadcell is now visible and has a white pad attached to it. Without touching the white pad, check it for damage. </li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/4f0b8b4b2de761bec7c838efa8152ca9_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="500" height="375" loading="lazy" /></p>
<ol start="4">
<li>Reassemble the block of PG-case, PG-ring, gearbox, and main plate. In case the parts are not in one block, follow the dedicated steps from the Nextruder <a href="http://help.prusa3d.com/attachment/ltlznibfugnpwtwy-jpg_272">assembly manual</a>, depending on your printer version. </li>
<li>Perform the <a href="http://help.prusa3d.com/article/gearbox-alignment-core-one-mk4-s-mk3-9-s_465779">gearbox alignment</a>. </li>
</ol>
</div>


Loadcell Timeout #31528 (CORE One) #26528 (MK4S) #13528 (MK4) #27528 (MK3.9S) #21528 (MK3.9)

<h3>What happened?</h3>
<p>The <strong>Prusa CORE One</strong>, and the <strong>Original Prusa MK4/S</strong>, <strong>MK3.9/S</strong> are equipped with a <strong>loadcell</strong>, which detects whether the nozzle is close enough to the steel sheet for printing and prevents damage from the nozzle digging into the steel sheet. </p>
<p>The loadcell measures the amount of force that the nozzle applies to the steel sheet. In case the measured value is abnormally high, or undefined, the printer will show the message <strong>"Loadcell measured an infinite or undefined load value."</strong></p>
<p>Error name: Loadcell Measure Failed</p>
<p>Error code: #31526 (CORE One) #26526 (MK4S) #13526 (MK4) #27526 (MK3.9S) #21526 (MK3.9)</p>
<h3>How to fix it? </h3>
<h4>A visual inspection</h4>
<div class="warning-callout">Before you start, make sure:</p>
<ul>
<li>the filament is unloaded from the extruder</li>
<li>the printer is turned OFF and unplugged from electricity</li>
<li>the hotend and the heatbed are cooled down to ambient temperature</li>
</ul>
</div>
<p>Access the right side of the LoveBoard, where the loadcell cable is connected. To remove the side LoveBoard cover, on CORE One loosen two<span style="color: #000000;"> <span style="color: #236fa1;"><strong>M3x6 bolts</strong></span></span>, on MK4/S and MK3.9/S loosen one <span style="color: #843fa1;"><strong>M3x10 bolt</strong></span>. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/c565b5d3a12f4e32b712cc273759d4e8_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Measure Failed REVIEW #31526 (CORE One) #26526 (MK4S) #13526 (MK4) #27526 (MK3.9S) #21526 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/94e576c7396585eb388df6fd136a8ec8_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p>Once accessed, locate the <span style="color: #e67e23;"><strong>loadcell connector</strong></span> and cable, and check for any loose cable, disconnected cable, or visible damage. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;">
<p style="text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/98f9151af765084ab2be69a52d63f20c_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></p>
</td>
<td style="width: 48.8562%; text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/3c492d1b5efc9c403a26bd3c455c2ea7_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/5e54e7bdd6fef88f48746c4095106a4f.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="500" height="375" loading="lazy" /></h4>
<h4>Re-test the loadcell</h4>
<div class="warning-callout">Do not manipulate or touch the printer unless the instructions on the printer screen prompt you to do so.</div>
<div>
<p>Navigate to <em>LCD Menu -&gt; Control -&gt; Calibrations &amp; Tests -&gt; Loadcell Test</em> to initiate a loadcell test. </p>
<p>During the test, you will be asked to tap the nozzle at a specific time, and a progress bar shown on the screen is filled, depending on the pressure applied to the loadcell. If the bar is not filled or is filled irregularly, please contact our <a href="http://help.prusa3d.com/article/customer-support_2287">customer support</a>. </p>
<div class="tip-callout">Tapping of the nozzle can be done with a finger, as well as with a hard object. </div>
<table style="border-collapse: collapse; width: 100%; border-style: none;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/e03a4297a772916ed43b160f9300a4b6_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/3226ee7326e5f8c4057eb46f4d9f8a55_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h3>Loadcell white pad - visual check </h3>
<div class="warning-callout">Ensure to have the <strong>PG-assembly-adapter</strong> before continuing with the following procedure. If you do not have it, you can print it using the below files, depending on the printer you will use: <br /><a href="https://files.printables.com/media/prints/451501/stls/4104840_55cb7d05-d1f6-4cca-8159-db9ac9f62942/pg-assembly-adapter-mk4-r1.stl">PG-assembly-adapter printed with MK4/S</a><br /><a href="https://files.printables.com/media/prints/451501/stls/4240522_6fa05937-693e-4282-8dce-a98d3e93fd5f/pg-assembly-adapter-mk3-r2.stl">PG-assembly-adapter printed with MK3/S/+</a></div>
<ol>
<li>If any filament is loaded, unload the filament, then wait for the printer to fully cool down. After that, turn the printer off.</li>
<li>Remove the PG-case, together with the PG-ring, gearbox, and main plate. Remove all of these parts in one piece. </li>
</ol>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/1c7df54642bb103d2a7d3ed01b41cbff_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/67c593556671a61a79c52036477d3454.jpg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<ol start="3">
<li>The top part of the loadcell is now visible and has a white pad attached to it. Without touching the white pad, check it for damage. </li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/4f0b8b4b2de761bec7c838efa8152ca9_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="500" height="375" loading="lazy" /></p>
<ol start="4">
<li>Reassemble the block of PG-case, PG-ring, gearbox, and main plate. In case the parts are not in one block, follow the dedicated steps from the Nextruder <a href="http://help.prusa3d.com/attachment/ltlznibfugnpwtwy-jpg_272">assembly manual</a>, depending on your printer version. </li>
<li>Perform the <a href="http://help.prusa3d.com/article/gearbox-alignment-core-one-mk4-s-mk3-9-s_465779">gearbox alignment</a>. </li>
</ol>
</div>


Loadcell Measure Failed #31526 (CORE One) #26526 (MK4S) #13526 (MK4) #27526 (MK3.9S) #21526 (MK3.9)

<h3>What happened?</h3>
<p>The <strong>Prusa CORE One</strong>, and the <strong>Original Prusa MK4/S</strong>, <strong>MK3.9/S</strong> are equipped with a <strong>loadcell</strong>, which detects whether the nozzle is close enough to the steel sheet for printing and prevents damage from the nozzle digging into the steel sheet. </p>
<p>During a selftest, the loadcell is tested. The loadcell can also be tested at any time through the printer menu. If the loadcell calibration is not done, or the printer does not recognize that it has been done, it will show the message: <strong>"Loadcell calibration is not finished. Finish the calibration first."</strong></p>
<p>Error name: Loadcell Not Calibrated</p>
<p>Error code: #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)</p>
<h3>How to fix it? </h3>
<h4>A visual inspection</h4>
<div class="warning-callout">Before you start, make sure:</p>
<ul>
<li>the filament is unloaded from the extruder</li>
<li>the printer is turned OFF and unplugged from electricity</li>
<li>the hotend and the heatbed are cooled down to ambient temperature</li>
</ul>
</div>
<p>Access the right side of the LoveBoard, where the loadcell cable is connected. To remove the side LoveBoard cover, on CORE One loosen two<span style="color: #000000;"> <span style="color: #236fa1;"><strong>M3x6 bolts</strong></span></span>, on MK4/S and MK3.9/S loosen one <span style="color: #843fa1;"><strong>M3x10 bolt</strong></span>. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/c565b5d3a12f4e32b712cc273759d4e8_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/94e576c7396585eb388df6fd136a8ec8_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p>Once accessed, locate the <span style="color: #e67e23;"><strong>loadcell connector</strong></span> and cable, and check for any loose cable, disconnected cable, or visible damage. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;">
<p style="text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/98f9151af765084ab2be69a52d63f20c_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></p>
</td>
<td style="width: 48.8562%; text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/3c492d1b5efc9c403a26bd3c455c2ea7_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/5e54e7bdd6fef88f48746c4095106a4f.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="500" height="375" loading="lazy" /></h4>
<h4>Re-test the loadcell</h4>
<div class="warning-callout">Do not manipulate or touch the printer unless the instructions on the printer screen prompt you to do so.</div>
<div>
<p>Navigate to <em>LCD Menu -&gt; Control -&gt; Calibrations &amp; Tests -&gt; Loadcell Test</em> to initiate a loadcell test. </p>
<p>During the test, you will be asked to tap the nozzle at a specific time, and a progress bar shown on the screen is filled, depending on the pressure applied to the loadcell. If the bar is not filled or is filled irregularly, please contact our <a href="http://help.prusa3d.com/article/customer-support_2287">customer support</a>. </p>
<div class="tip-callout">Tapping of the nozzle can be done with a finger, as well as with a hard object. </div>
<table style="border-collapse: collapse; width: 100%; border-style: none;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/e03a4297a772916ed43b160f9300a4b6_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/3226ee7326e5f8c4057eb46f4d9f8a55_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h3>Loadcell white pad - visual check </h3>
<div class="warning-callout">Ensure to have the <strong>PG-assembly-adapter</strong> before continuing with the following procedure. If you do not have it, you can print it using the below files, depending on the printer you will use: <br /><a href="https://files.printables.com/media/prints/451501/stls/4104840_55cb7d05-d1f6-4cca-8159-db9ac9f62942/pg-assembly-adapter-mk4-r1.stl">PG-assembly-adapter printed with MK4/S</a><br /><a href="https://files.printables.com/media/prints/451501/stls/4240522_6fa05937-693e-4282-8dce-a98d3e93fd5f/pg-assembly-adapter-mk3-r2.stl">PG-assembly-adapter printed with MK3/S/+</a></div>
<ol>
<li>If any filament is loaded, unload the filament, then wait for the printer to fully cool down. After that, turn the printer off.</li>
<li>Remove the PG-case, together with the PG-ring, gearbox, and main plate. Remove all of these parts in one piece. </li>
</ol>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/1c7df54642bb103d2a7d3ed01b41cbff_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/67c593556671a61a79c52036477d3454.jpg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<ol start="3">
<li>The top part of the loadcell is now visible and has a white pad attached to it. Without touching the white pad, check it for damage. </li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/4f0b8b4b2de761bec7c838efa8152ca9_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="500" height="375" loading="lazy" /></p>
<ol start="4">
<li>Reassemble the block of PG-case, PG-ring, gearbox, and main plate. In case the parts are not in one block, follow the dedicated steps from the Nextruder <a href="http://help.prusa3d.com/attachment/ltlznibfugnpwtwy-jpg_272">assembly manual</a>, depending on your printer version. </li>
<li>Perform the <a href="http://help.prusa3d.com/article/gearbox-alignment-core-one-mk4-s-mk3-9-s_465779">gearbox alignment</a>. </li>
</ol>
</div>


Loadcell Not Calibrated #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)

<h3>What happened?</h3>
<p>The printer is showing the message <strong>"Check the heatbreak thermistor wiring for possible damage."</strong></p>
<p>Error name: Heatbreak MAXTEMP Error</p>
<p>Error code: #26212 (MK4S) #13212 (MK4) #27212 (MK3.9S) #21212 (MK3.9)</p>
<p>The error is shown when the heatbreak thermistor measures over 100 ºC at any point.</p>
<h3>How to fix it? </h3>
<p>Access the LoveBoard. Check if the thermistor is connected correctly and if there is no damage along the cable length.</p>
<p>If you have a multimeter, it is possible to check the resistance of the cables to verify if they are damaged. For that, use our <a href="http://help.prusa3d.com/article/multimeter-usage_2117">Multimeter usage</a> guide.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/4d8068ede1cb7f665960fe46fa065702.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Heatbreak MAXTEMP Error #13212 (MK4)" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/58ffb6b72e3e8d3b_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Heatbreak MINTEMP Error #13211" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p> </p>


Heatbreak MAXTEMP Error #26212 (MK4S) #13212 (MK4) #27212 (MK3.9S) #21212 (MK3.9)

<h3>What happened?</h3>
<p>The printer is showing the error <strong>"Check the heatbed thermistor wiring for possible damage."</strong></p>
<p>Error name: Bed Maxtemp error </p>
<p>Error code: #26205 (MK4S) #13205 (MK4) #27205 (MK3.9S) #21205 (MK3.9) #28205 (MK3.5S) #23205 (MK3.5)</p>
<p>The error happens when the printer's heatbed temperature goes above <strong>125 ºC</strong> at any point. This is a safety feature to prevent printer damage. In this case, the printer will stop the heating and display the message on the screen.</p>
<h3>How to fix it?</h3>
<p>Make sure that the <strong>ambient temperature</strong> where the printer is is stable, and above <strong>10 ºC</strong>.</p>
<p>This error is usually caused by a damaged <strong>heatbed thermistor</strong>.</p>
<div class="tip-callout">Doing regular maintenance on the printer may prevent this type of issue.</div>
<p>Check if the thermistor is well secured under the <strong>golden Kapton tape</strong>.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/Heatbedthermistor.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Maxtemp error #13205 (FIONA)" alt="" width="500" height="375" loading="lazy" /></p>
<p>In order to test if the thermistor is damaged, go to the printer menu in <em>Settings -&gt; Temperature -&gt; Heatbed temperature</em>, and set it to <strong>80 ºC</strong>. Then, move the heabed cables by hand and see if the temperature will fluctuate. If the temperature fluctuates more than <strong>5 ºC</strong>, from the set temperature, the thermistor needs to be replaced.</p>
<p>Open the <strong>xBuddyBox-cover</strong> and the <strong>el-box-cover</strong> by opening the screws indicated below to access the heatbed cable connectors. Make sure that the heatbed power cable did not slip from the screw, and that the heatbed thermistor cable is well connected.</p>
<p>If you have a <strong>multimeter</strong>, you can check the resistance of the cables using this guide: <a href="http://help.prusa3d.com/article/multimeter-usage_2117">Multimeter usage</a></p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/ef0adcc4ba6782d2_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Thermal runaway #13203 (FIONA)" alt="" width="400" height="267" loading="lazy" /></td>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/783109cb80ab5ceb_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Thermal runaway #13203 (FIONA)" alt="" width="400" height="267" loading="lazy" /></td>
</tr>
</tbody>
</table>


Bed maxtemp error #26205 (MK4S) #13205 (MK4) #27205 (MK3.9S) #21205 (MK3.9) #28205 (MK3.5S) #23205 (MK3.5)

<h3>What happened?</h3>
<p>The <strong>Prusa CORE One</strong>, and the <strong>Original Prusa MK4/S</strong>, <strong>MK3.9/S</strong> are equipped with a <strong>loadcell</strong>, which detects whether the nozzle is close enough to the steel sheet for printing and prevents damage from the nozzle digging into the steel sheet. </p>
<p>In case the printer detects an incorrect loadcell configuration, but not related to the loadcell tare, or to the loadcell calibration, the printer will show the message: <strong>"The loadcell configuration is incorrect."</strong></p>
<p>Error name: Loadcell Bad Configuration</p>
<p>Error code: #31527 (CORE One) #26527 (MK4S) #13527 (MK4) #27527 (MK3.9S) #21527 (MK3.9)</p>
<h3>How to fix it? </h3>
<h4>A visual inspection</h4>
<div class="warning-callout">Before you start, make sure:</p>
<ul>
<li>the filament is unloaded from the extruder</li>
<li>the printer is turned OFF and unplugged from electricity</li>
<li>the hotend and the heatbed are cooled down to ambient temperature</li>
</ul>
</div>
<p>Access the right side of the LoveBoard, where the loadcell cable is connected. To remove the side LoveBoard cover, on CORE One loosen two<span style="color: #000000;"> <span style="color: #236fa1;"><strong>M3x6 bolts</strong></span></span>, on MK4/S and MK3.9/S loosen one <span style="color: #843fa1;"><strong>M3x10 bolt</strong></span>. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/c565b5d3a12f4e32b712cc273759d4e8_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Bad Configuration REVIEW #31527 (CORE One) #26527 (MK4S) #13527 (MK4) #27527 (MK3.9S) #21527 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/94e576c7396585eb388df6fd136a8ec8_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p>Once accessed, locate the <span style="color: #e67e23;"><strong>loadcell connector</strong></span> and cable, and check for any loose cable, disconnected cable, or visible damage. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;">
<p style="text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/98f9151af765084ab2be69a52d63f20c_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></p>
</td>
<td style="width: 48.8562%; text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/3c492d1b5efc9c403a26bd3c455c2ea7_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/5e54e7bdd6fef88f48746c4095106a4f.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="500" height="375" loading="lazy" /></h4>
<h4>Re-test the loadcell</h4>
<div class="warning-callout">Do not manipulate or touch the printer unless the instructions on the printer screen prompt you to do so.</div>
<div>
<p>Navigate to <em>LCD Menu -&gt; Control -&gt; Calibrations &amp; Tests -&gt; Loadcell Test</em> to initiate a loadcell test. </p>
<p>During the test, you will be asked to tap the nozzle at a specific time, and a progress bar shown on the screen is filled, depending on the pressure applied to the loadcell. If the bar is not filled or is filled irregularly, please contact our <a href="http://help.prusa3d.com/article/customer-support_2287">customer support</a>. </p>
<div class="tip-callout">Tapping of the nozzle can be done with a finger, as well as with a hard object. </div>
<table style="border-collapse: collapse; width: 100%; border-style: none;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/e03a4297a772916ed43b160f9300a4b6_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/3226ee7326e5f8c4057eb46f4d9f8a55_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h3>Loadcell white pad - visual check </h3>
<div class="warning-callout">Ensure to have the <strong>PG-assembly-adapter</strong> before continuing with the following procedure. If you do not have it, you can print it using the below files, depending on the printer you will use: <br /><a href="https://files.printables.com/media/prints/451501/stls/4104840_55cb7d05-d1f6-4cca-8159-db9ac9f62942/pg-assembly-adapter-mk4-r1.stl">PG-assembly-adapter printed with MK4/S</a><br /><a href="https://files.printables.com/media/prints/451501/stls/4240522_6fa05937-693e-4282-8dce-a98d3e93fd5f/pg-assembly-adapter-mk3-r2.stl">PG-assembly-adapter printed with MK3/S/+</a></div>
<ol>
<li>If any filament is loaded, unload the filament, then wait for the printer to fully cool down. After that, turn the printer off.</li>
<li>Remove the PG-case, together with the PG-ring, gearbox, and main plate. Remove all of these parts in one piece. </li>
</ol>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/1c7df54642bb103d2a7d3ed01b41cbff_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/67c593556671a61a79c52036477d3454.jpg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<ol start="3">
<li>The top part of the loadcell is now visible and has a white pad attached to it. Without touching the white pad, check it for damage. </li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/4f0b8b4b2de761bec7c838efa8152ca9_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="500" height="375" loading="lazy" /></p>
<ol start="4">
<li>Reassemble the block of PG-case, PG-ring, gearbox, and main plate. In case the parts are not in one block, follow the dedicated steps from the Nextruder <a href="http://help.prusa3d.com/attachment/ltlznibfugnpwtwy-jpg_272">assembly manual</a>, depending on your printer version. </li>
<li>Perform the <a href="http://help.prusa3d.com/article/gearbox-alignment-core-one-mk4-s-mk3-9-s_465779">gearbox alignment</a>. </li>
</ol>
</div>


Loadcell Bad Configuration #31527 (CORE One) #26527 (MK4S) #13527 (MK4) #27527 (MK3.9S) #21527 (MK3.9)

<h3>What happened?</h3>
<p>The printer is showing the message <strong>"Check the heatbreak thermistor wiring for possible damage."</strong></p>
<p>Error name: Heatbreak MINTEMP Error</p>
<p>Error code: #26211 (MK4S) #13211 (MK4) #27211 (MK3.9S) #21211 (MK3.9)</p>
<p>The error is shown when the heatbreak thermistor drops below <strong>5 ºC </strong>at any point.</p>
<h3>How to fix it?</h3>
<p>Access the LoveBoard. Check if the thermistor is connected correctly and if there is no damage along the cable length.</p>
<p>If you have a multimeter, it is possible to check the resistance of the cables to verify if they are damaged. For that, use our <a href="http://help.prusa3d.com/article/multimeter-usage_2117">Multimeter usage</a> guide.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/4d8068ede1cb7f665960fe46fa065702.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Heatbreak MINTEMP Error #13211" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/58ffb6b72e3e8d3b_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Heatbreak MINTEMP Error #13211" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p> </p>


Heatbreak MINTEMP Error #26211 (MK4S) #13211 (MK4) #27211 (MK3.9S) #21211 (MK3.9)

<h3>What happened?</h3>
<p>The printer is showing the message <strong>"Check the print head thermistor wiring for possible damage."</strong></p>
<p>Error name: Hotend Maxtemp error</p>
<p>Error code: #26201 (MK4S) #13201 (MK4)  # 27201 (MK3.9S) #21201 (MK3.9) #28201 (MK3.5S) #23201 (MK3.5) #31201 (CORE One)</p>
<p>This error is shown when the printer's nozzle temperature goes above <strong>305 ºC</strong> at any point. This is a safety feature to prevent printer damage. The print will be stopped and the printer will cool down.</p>
<h3>How to fix it?</h3>
<h4>Extruder inspection</h4>
<p>This error is usually caused by the <strong>hotend thermistor</strong>. </p>
<p>Access the LoveBoard. Check if the thermistor is connected correctly and if there is no damage along the cable length.</p>
<p>If you have a multimeter, it is possible to check the resistance of the cables to verify if they are damaged. For that, use our <a href="http://help.prusa3d.com/article/multimeter-usage_2117">Multimeter usage</a> guide.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/4d8068ede1cb7f665960fe46fa065702.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Hotend maxtemp error #13206 (MK4)" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8358%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/03/b1fcbf1f9cc8f479_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Maxtemp error #13206 (FIONA)" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4>xBuddy board inspection</h4>
<p>Make sure that the Loveboard main cable is correctly connected to the <strong>xBuddy board</strong>.</p>


Hotend maxtemp error #26201 (MK4S) #13201 (MK4)  # 27201 (MK3.9S) #21201 (MK3.9) #28201 (MK3.5S) #23201 (MK3.5) #31201 (CORE One)

<h3>What happened?</h3>
<p>When trying to install non-official firmware on your Original Prusa MK4/S, MK3.9/S, or MK3.5/S, the screen shows "<strong>Firmware signature verification failed! Only official signed firmware can be flashed</strong>".</p>
<p>Error name: Signature verification failed</p>
<p>Error code: #26606 (MK4S) #13606 (MK4) #27606 (MK3.9S) #21606 (MK3.9) #28606 (MK3.5S) #23606 (MK3.5) </p>
<p>The error is issued when your printer has detected an attempt to flash firmware that does not have the private key signature that verifies the firmware as being official.</p>
<h3>How to fix it?</h3>
<p>The Original Prusa MK4/S, MK3.9/S, and MK3.5/S in their factory state only accept official firmware. In order to flash a custom firmware, you need to break the <strong>appendix seal</strong> on the <strong>xBuddy board</strong>. </p>
<div class="warning-callout">Breaking the <strong>appendix seal won’t void your warranty</strong>, so you are free to flash custom firmware.<br />However, since there is no way for us to verify or test every single custom firmware on the internet, <strong>we disclaim liability for any kind of damage or harm a printer with a broken seal may cause</strong> (e.g. in case of a fire). <br />So, please, don’t mindlessly flash suspicious files! </div>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/04/9e2b3d5d8e34750731b95fc19df8905d.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Signature verification failed #13606 (MK4) #21606 (MK3.9) #23606 (MK3.5)" alt="" width="500" height="376" loading="lazy" /></p>


Signature verification failed #26606 (MK4S) #13606 (MK4) #27606 (MK3.9S) #21606 (MK3.9) #28606 (MK3.5S) #23606 (MK3.5)

<h3>What happened?</h3>
<p>The <strong>Prusa CORE One</strong>, and the <strong>Original Prusa MK4/S, MK3.9/S</strong> are equipped with a <strong>loadcell</strong>, to detect that the nozzle is close enough to the steel sheet for printing, and to avoid damage that would be caused by the nozzle digging into the steel sheet. </p>
<p>The loadcell sets itself a reference, called <strong>tare</strong>. In case there is an issue right before the start of this procedure, the printer will show the message: <strong>"There was an error requesting the tare for loadcell."</strong></p>
<p>Error name: Loadcell Tare Error</p>
<p>Error code: #31524 (CORE One) #26524 (MK4S) #13524 (MK4) #27524 (MK3.9S) #21524 (MK3.9)</p>
<h3>How to fix it? </h3>
<h4>A visual inspection</h4>
<div class="warning-callout">Before you start, make sure:</p>
<ul>
<li>the filament is unloaded from the extruder</li>
<li>the printer is turned OFF and unplugged from electricity</li>
<li>the hotend and the heatbed are cooled down to ambient temperature</li>
</ul>
</div>
<p>Access the right side of the LoveBoard, where the loadcell cable is connected. To remove the side LoveBoard cover, on CORE One loosen two<span style="color: #000000;"> <span style="color: #236fa1;"><strong>M3x6 bolts</strong></span></span>, on MK4/S and MK3.9/S loosen one <span style="color: #843fa1;"><strong>M3x10 bolt</strong></span>. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/c565b5d3a12f4e32b712cc273759d4e8_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Tare Error REVIEW #31524 (CORE One) #26524 (MK4S) #13524 (MK4) #27524 (MK3.9S) #21524 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/94e576c7396585eb388df6fd136a8ec8_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p>Once accessed, locate the <span style="color: #e67e23;"><strong>loadcell connector</strong></span> and cable, and check for any loose cable, disconnected cable, or visible damage. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;">
<p style="text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/98f9151af765084ab2be69a52d63f20c_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></p>
</td>
<td style="width: 48.8562%; text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/3c492d1b5efc9c403a26bd3c455c2ea7_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/5e54e7bdd6fef88f48746c4095106a4f.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="500" height="375" loading="lazy" /></h4>
<h4>Re-test the loadcell</h4>
<div class="warning-callout">Do not manipulate or touch the printer unless the instructions on the printer screen prompt you to do so.</div>
<div>
<p>Navigate to <em>LCD Menu -&gt; Control -&gt; Calibrations &amp; Tests -&gt; Loadcell Test</em> to initiate a loadcell test. </p>
<p>During the test, you will be asked to tap the nozzle at a specific time, and a progress bar shown on the screen is filled, depending on the pressure applied to the loadcell. If the bar is not filled or is filled irregularly, please contact our <a href="http://help.prusa3d.com/article/customer-support_2287">customer support</a>. </p>
<div class="tip-callout">Tapping of the nozzle can be done with a finger, as well as with a hard object. </div>
<table style="border-collapse: collapse; width: 100%; border-style: none;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/e03a4297a772916ed43b160f9300a4b6_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/3226ee7326e5f8c4057eb46f4d9f8a55_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h3>Loadcell white pad - visual check </h3>
<div class="warning-callout">Ensure to have the <strong>PG-assembly-adapter</strong> before continuing with the following procedure. If you do not have it, you can print it using the below files, depending on the printer you will use: <br /><a href="https://files.printables.com/media/prints/451501/stls/4104840_55cb7d05-d1f6-4cca-8159-db9ac9f62942/pg-assembly-adapter-mk4-r1.stl">PG-assembly-adapter printed with MK4/S</a><br /><a href="https://files.printables.com/media/prints/451501/stls/4240522_6fa05937-693e-4282-8dce-a98d3e93fd5f/pg-assembly-adapter-mk3-r2.stl">PG-assembly-adapter printed with MK3/S/+</a></div>
<ol>
<li>If any filament is loaded, unload the filament, then wait for the printer to fully cool down. After that, turn the printer off.</li>
<li>Remove the PG-case, together with the PG-ring, gearbox, and main plate. Remove all of these parts in one piece. </li>
</ol>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/1c7df54642bb103d2a7d3ed01b41cbff_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/67c593556671a61a79c52036477d3454.jpg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<ol start="3">
<li>The top part of the loadcell is now visible and has a white pad attached to it. Without touching the white pad, check it for damage. </li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/4f0b8b4b2de761bec7c838efa8152ca9_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="500" height="375" loading="lazy" /></p>
<ol start="4">
<li>Reassemble the block of PG-case, PG-ring, gearbox, and main plate. In case the parts are not in one block, follow the dedicated steps from the Nextruder <a href="http://help.prusa3d.com/attachment/ltlznibfugnpwtwy-jpg_272">assembly manual</a>, depending on your printer version. </li>
<li>Perform the <a href="http://help.prusa3d.com/article/gearbox-alignment-core-one-mk4-s-mk3-9-s_465779">gearbox alignment</a>. </li>
</ol>
</div>


Loadcell Tare Error #31524 (CORE One) #26524 (MK4S) #13524 (MK4) #27524 (MK3.9S) #21524 (MK3.9)

<h3>What happened?</h3>
<p>The <strong>Prusa CORE One</strong>, and the <strong>Original Prusa MK4/S</strong>, <strong>MK3.9/S</strong> are equipped with a <strong>loadcell</strong>, which detects whether the nozzle is close enough to the steel sheet for printing and prevents damage from the nozzle digging into the steel sheet. </p>
<p>The loadcell sets itself a reference, called <strong>tare</strong>. In case there is an issue during this procedure, the printer will show the message: <strong>"Setting the tare failed. Check the loadcell wiring and connection."</strong></p>
<p>Error name: Loadcell Tare Failed </p>
<p>Error code: #31525 (CORE One) #26525 (MK4S) #13525 (MK4) #27525 (MK3.9S) #21525 (MK3.9)</p>
<h3>How to fix it? </h3>
<h4>A visual inspection</h4>
<div class="warning-callout">Before you start, make sure:</p>
<ul>
<li>the filament is unloaded from the extruder</li>
<li>the printer is turned OFF and unplugged from electricity</li>
<li>the hotend and the heatbed are cooled down to ambient temperature</li>
</ul>
</div>
<p>Access the right side of the LoveBoard, where the loadcell cable is connected. To remove the side LoveBoard cover, on CORE One loosen two<span style="color: #000000;"> <span style="color: #236fa1;"><strong>M3x6 bolts</strong></span></span>, on MK4/S and MK3.9/S loosen one <span style="color: #843fa1;"><strong>M3x10 bolt</strong></span>. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/c565b5d3a12f4e32b712cc273759d4e8_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Tare Failed REVIEW #31525 (CORE One) #26525 (MK4S) #13525 (MK4) #27525 (MK3.9S) #21525 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/94e576c7396585eb388df6fd136a8ec8_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p>Once accessed, locate the <span style="color: #e67e23;"><strong>loadcell connector</strong></span> and cable, and check for any loose cable, disconnected cable, or visible damage. </p>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;">
<p style="text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/98f9151af765084ab2be69a52d63f20c_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></p>
</td>
<td style="width: 48.8562%; text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/3c492d1b5efc9c403a26bd3c455c2ea7_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2025/01/5e54e7bdd6fef88f48746c4095106a4f.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell Not Calibrated REVIEW #31523 (CORE One) #26523 (MK4S) #13523 (MK4) #27523 (MK3.9S) #21523 (MK3.9)" alt="" width="500" height="375" loading="lazy" /></h4>
<h4>Re-test the loadcell</h4>
<div class="warning-callout">Do not manipulate or touch the printer unless the instructions on the printer screen prompt you to do so.</div>
<div>
<p>Navigate to <em>LCD Menu -&gt; Control -&gt; Calibrations &amp; Tests -&gt; Loadcell Test</em> to initiate a loadcell test. </p>
<p>During the test, you will be asked to tap the nozzle at a specific time, and a progress bar shown on the screen is filled, depending on the pressure applied to the loadcell. If the bar is not filled or is filled irregularly, please contact our <a href="http://help.prusa3d.com/article/customer-support_2287">customer support</a>. </p>
<div class="tip-callout">Tapping of the nozzle can be done with a finger, as well as with a hard object. </div>
<table style="border-collapse: collapse; width: 100%; border-style: none;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/e03a4297a772916ed43b160f9300a4b6_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/3226ee7326e5f8c4057eb46f4d9f8a55_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h3>Loadcell white pad - visual check </h3>
<div class="warning-callout">Ensure to have the <strong>PG-assembly-adapter</strong> before continuing with the following procedure. If you do not have it, you can print it using the below files, depending on the printer you will use: <br /><a href="https://files.printables.com/media/prints/451501/stls/4104840_55cb7d05-d1f6-4cca-8159-db9ac9f62942/pg-assembly-adapter-mk4-r1.stl">PG-assembly-adapter printed with MK4/S</a><br /><a href="https://files.printables.com/media/prints/451501/stls/4240522_6fa05937-693e-4282-8dce-a98d3e93fd5f/pg-assembly-adapter-mk3-r2.stl">PG-assembly-adapter printed with MK3/S/+</a></div>
<ol>
<li>If any filament is loaded, unload the filament, then wait for the printer to fully cool down. After that, turn the printer off.</li>
<li>Remove the PG-case, together with the PG-ring, gearbox, and main plate. Remove all of these parts in one piece. </li>
</ol>
<table style="border-collapse: collapse; width: 100%;" border="1">
<tbody>
<tr>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/1c7df54642bb103d2a7d3ed01b41cbff_painted.jpeg" alt="" width="395" height="296" loading="lazy" /></td>
<td style="width: 48.8562%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/10/67c593556671a61a79c52036477d3454.jpg" alt="" width="395" height="296" loading="lazy" /></td>
</tr>
</tbody>
</table>
<ol start="3">
<li>The top part of the loadcell is now visible and has a white pad attached to it. Without touching the white pad, check it for damage. </li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/11/4f0b8b4b2de761bec7c838efa8152ca9_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Loadcell troubleshooting" alt="" width="500" height="375" loading="lazy" /></p>
<ol start="4">
<li>Reassemble the block of PG-case, PG-ring, gearbox, and main plate. In case the parts are not in one block, follow the dedicated steps from the Nextruder <a href="http://help.prusa3d.com/attachment/ltlznibfugnpwtwy-jpg_272">assembly manual</a>, depending on your printer version. </li>
<li>Perform the <a href="http://help.prusa3d.com/article/gearbox-alignment-core-one-mk4-s-mk3-9-s_465779">gearbox alignment</a>. </li>
</ol>
</div>


Loadcell Tare Failed #31525 (CORE One) #26525 (MK4S) #13525 (MK4) #27525 (MK3.9S) #21525 (MK3.9)


<ul>
<li>Prusa Connect integration</li>



<li>Prusa Account integration</li>



<li>Improved UI</li>



<li>Improved G-code Viewer</li>



<li>New system profile updating system</li>



<li>Single Perimeter for top and bottom layers</li>



<li>Extended SLA layer separation configuration</li>



<li>Bug fixes</li>
</ul>


2.8.0

1.00


<ul>
<li>Issues with numeric keyboard repaired (MK4/S, MK3.9/S, MK3.5/S, XL)</li>



<li>Returned nozzle diameter setup (XL)</li>



<li>Printhead position during calibrations changed (MK4/S, MK3.9/S, MK3.5/S)</li>



<li>Cold pull (XL)</li>
</ul>


6.1.3


<ul>
<li>Improved menu bar, the menu no longer hides under a button</li>



<li>Two new parameters (Abrasive material and High flow nozzle) for G-Code checks</li>



<li>Improved automatic orientation of bridges</li>



<li>Number of bugfixes</li>
</ul>


2.8.1


<p>Correction of product information</p>



<p>Minor content updates</p>


1.01


<ul>
<li>Multiple beds and bulk export</li>



<li>Scarf seams</li>



<li>Printables integration</li>



<li>Paint-on fuzzy skin</li>



<li>Improvements in painting tools and multi-material slicing</li>



<li>Basic support for printing with different nozzle diameters</li>
</ul>


2.9.0


<ul>
<li>Added an option to save printer logs to a text file</li>



<li>Expanded GPIO functionality (MK4/S, MK3.9/S, MK3.5/S)</li>



<li>Toolhead and hardware menu overhaul</li>



<li>Improved filament management</li>



<li>“Set Ready” button</li>



<li>Connect header status icon</li>



<li>Nozzle information for Prusa Connect</li>



<li>Mapping screen from Prusa Connect</li>



<li>Japanese language support on MINI</li>
</ul>


Original Prusa MK3.9S

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