LCD screen not working

Updated 1 month ago ​by Tomáš Chvalina

The LCD screen is vital for operating the printer. Should you encounter any kind of trouble, such as a dead screen, corrupted text or other issues, please refer to our guide below. 

Blank LCD screen

This problem usually appears only on user-assembled printers. If your printer's LCD screen remains blank or displays corrupted symbols after you turn on the printer, there is a chance it is caused by incorrect wiring. Follow these steps to fix the issue.

  1. Turn the printer off, remove the power cord and unplug the printer's USB cable from PC
  2. Open the cover of the electronics board.
    1. Original Prusa i3 MK3 EINSY board can be accessed by reverting STEP 31 in the Electronics assembly.
    2. Original Prusa i3 MK2/S miniRAMBo board can be accessed by reverting STEP 21 in the Electronics assembly.
  3. Double-check that all cables are properly seated and they are not visibly damaged. Depending on the model of your printer, please refer to the following guides for information on how to make sure the cables are properly connected: MK3 EINSY miniRAMBo electronics wiring and MK2/MK2S miniRAMBo electronics wiring.
  4. Make sure that the LCD ribbon cables are not badly warped at any spot and that they are fully seated in the correct connector with the correct orientation. See the MK2 assembly manual or MK3 assembly manual for detailed instructions.
  5. If you suspect that the LCD ribbon cables connectors are not firmly seated in the slots, disconnect the LCD ribbon cables and check the slots for any bent pins. If there are bent pins, you can use tweezers to fix them. However, be very careful not to break the pin(s) completely.
  6. Gently push the connectors back into their respective slots. Then reconnect the power cord and turn the printer on again. 

  7. If none of the above resolved the problem, turn the printer off again and try to unplug both of the cables, lay them down on a flat surface and gently stretch them. Then plug them back in and turn on the printer.

Do not hesitate to contact us at info@prusa3d.com if none of that solved the problem. 

Squares on the LCD screen

Firmware updates are necessary to keep your printer up to date. However, installation of an incorrect firmware can lead to letter corruption on the LCD screen. There's an easy fix, though:

  1. Go to the prusa3d.com/drivers/ and download the correct firmware version for your printer setup. 
  2. Pay attention to the RED labeled text under the firmware version. In the example below, the firmware update is compatible ONLY with the Original Prusa i3 MK3.

     
  3. Once you download the correct zip file, simply follow the Firmware upgrade and flashing instructions and you are good to go.
There's a small chance you could potentially damage your printer's LCD screen by an electrostatic discharge when inserting the SD card. Please contact us at info@prusa3d.com if that happens.

Do not hesitate to contact us at info@prusa3d.com if you would have any further questions.


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