Core One just sits idle and won't start a print
Finished building my Core One and did an initial print of the included keychain file with no problems. A day later and I cannot get it to start a new print; it will idle at printing temp for 20+ minutes with no progress. No errors. Just sits idle.
It initially passed all sensor tests and is not displaying any error messages. Yesterday while trying to print I received a Hotend preheat error #31202 several times and the machine would reboot. I checked the wiring and removed / reinstalled the nozzle and could not find any issues.
At this point I'm thinking there may be an issue with one of the machine parts but before I start going through troubleshooting with Prusa tech support, I'm hoping someone will offer a suggestion that I can check. Also, just for context, I built a mk3s+ approximately 5 years ago and have been printing on it through the years with little to no issues. I'm not a complete novice to building and printing with Prusa machines, but this one has me stumped.
RE: Core One just sits idle and won't start a print
Take a look at this page, it describes your problem and has potential solutions:
https://help.prusa3d.com/article/hotend-preheat-error-26202-mk4s-13202-mk4-27202-mk3-9s-21202-mk3-9-31202-core-one_401060
UPDATE: Core One just sits idle and won't start a print
Connected with Prusa tech support via chat and they were able to help me diagnose the problem fairly quickly. Used a voltmeter to test the ohms resistance of the thermistor. https://help.prusa3d.com/article/multimeter-usage_2117
Turns out the voltage on my thermistor was fluctuating from 103 ohms down to high 70's whenever the wire was touched. Removed the nextruder hotend assembly and then tried to remove the thermistor but found the set screw was overtorqued when assembled at the factory which appeared to have flattened (and I believe partially crush the end) of the thermistor. Prusa is sending me another heater block and thermistor. Hopefully this will fix all of the problems that I've been having.