What happened?
The printer will display the message "Extruder Mintemp error: Check the thermistor wiring for potential damage" if the printer's nozzle temperature goes below 15 ºC at any point. In this case, the printer will stop the heating and display the message on the screen. The printer then waits for the user to inspect all parts and if needed fix the issue.
Error name: Hotend mintemp error
Error code: #17208
How to fix it?
Most often, this error happens due to wiring damage or connection issue on the hotend thermistor cable. Less often, it might be caused by the hotend heater wiring and connection.
A visual inspection
Before breaking out the multimeter you should check the Dwarf board, where the thermistor and heater reside, to ensure that no wires have broken off, or are disconnected.
- the filament is unloaded from the extruder
- the printer is turned OFF and unplugged from electricity
- the hotend and the heatbed are cooled down to ambient temperature
Place an empty Prusament cardboard box approximately to the front center part of the heated. Move the X-axis all the way to the front side of the printer, and move the extruder approximately to the center of the X-axis.
Open the dwarf-cover-door to access the Dwarf board.
Check that all the connectors are secure in their sockets, according to the picture below. Focus on the thermistor and heater cables. Though unlikely, rough shipping or handling could have shaken the heater or thermistor cables loose.
Checking the resistance
The table below describes the correct resistance for each part, as well as what scale you should set your meter to. The hotend thermistor is rated to be 100 kΩ at 25 °C. To be realistic, with a varying temperature between 20 °C and 30 °C, you can expect a wider range of readings (~85-125 kΩ).
There can be micro-fractures in the cable, breaking the connections only at certain positions. Therefore, try to move the cable a bit while doing the measurement and see if the value changes drastically.
Part |
Resistance |
Multimeter scale |
|
Hotend thermistor |
[80 kΩ - 125 kΩ] |
200 kΩ |
|
Hotend heater |
[12.3 Ω - 15.1 Ω] |
200 Ω |
6 comments
No matter what I did to try to fix this problem it would still give the error. Upon taking the thermistor out of the hot-end, I found that the actual thermistor was DENTED near the tip, from the factory due to the grub screw being over-tightened.
Luckily, I had purchased a new thermistor last year as a spare and swapped out the defective one. I went to "control" option and manually set the temperature to 190 degrees C. The hotend with the installed new thermistor heated up to the set temperature and did NOT give any errors.
I started an actual print, and the error seems to have disappeared. The fix was swapping out the defective and dented from the factory thermistor.
I took a picture of the damaged thermistor, but do not know how to post or give this picture out for viewing or review.
I hope this manages to help others out experiencing this same problem.
https://help.prusa3d.com/article/multimeter-usage_2117