I also get MINTEMP error. I got one after a few weeks of not using the Mini. It was resolved by using a hairdryer to up the temp of nozzle and bed (I live in a draughty old farmhouse, in Scotland...). However, after removing, cleaning and returning the nozzle it has become unfixable.
How do you know whether the thermistor is damaged?
You can check the internal resistance of a thermistor with a multimeter. The value should be measured at an ambient temperature of 25 degrees C. should be about 100kohms. The polarity of the measuring tips does not matter when measuring a resistance.
Simply remove the plug from the printerboard and measure.
Thanks for the suggestion. As it happens I have a simple multimeter. Now I just need to work out where to touch the probes...
If I make any progress I'll post back the solution...
i also have this error
started happening after i flashed firmware to 4.2.1.
had 4.0.5 before and it worked perfectly fine
i tried flashing it back down, 4.1.0 had the same problem, 4.0.4 made the bed teeth jump in calibration and watchdog out, and now i have the same issue in 4.0.5
i dont know what is going on, but its pretty demoralizing
here a short introduction:
I have a similar problem with my mk3s (self build kit) that I have for about 2 months now. This first four weeks everything worked just fine. But after the firmware update I get a Bed Mintemp error at point 7 of the z calibration procedure (the one that the printer does before every print).
The printer request me to restart. After that it works just fine.
So I believe it is not a problem of broken cables or sensors, because the error occures exactly at the same point of the procedure and only once. After restart it proceeds throught the z calibration without any problem and finishes the print job.
This is very annoying, because it costs me extra minutes very time to restart, reheat and start the print job again.
I tried reinstalling the firmware - but it didn't help. I didn't try going back to the previous firmware, because it feels wrong somehow. But if that is a suggestion I would give that a try.
i spoke with support, described my symptoms and they said that it indeed is the thermocouple acting up and sent a replacement...
in my case i think its the wires to it being damaged because its not consistent and usually after the bed moves
Thank you for the video. I acquired a multimeter and by testing have established that the hot-end thermistor is most likely broken as when I remove the plug from the board and test across the two terminals I get a reading of 1.
To be honest I am disappointed in how delicate this part of the Mini seems to be. I only followed the instructions to remove and replace the nozzle. I guess I will have to order and fit a new hot-end thermistor...
1 means infinite resistance, i.e. thermistor or cable/s defective. I assume that the problem will be solved with a new thermistor.
good luck with the installation and take care of the sensitive wires 👍
I had a chat with customer support and they have sent me a replacement thermistor.
Although I was disappointed with the thermistor I am impressed with the customer service!