Extruder Temp Fluctuating and MAXTEMP Error


My Wilson II printer has been rock solid for almost 2 years now, but lately the extruder temperature has been fluctuating while printing to the point where it gives a max temp error and stops. From reading other discussions I’m thinking a short in the thermistor wire is the most likely cause. I plan to try replacing the thermistor with a generic one from my old 3d printer, but wanted to see if anyone else had any advice to offer. Thanks in advance!


I wasn’t able to get the thermistor out of the heater block so I replaced the whole E3D V6 lite hot end with another I had from my old printer, but it’s still having the same problem. When I tell it to “PreHeat PLA” it fluctuates between 176 and 183 so I’m thinking there is still an issue. The power supply makes a buzzing noise when first turned on. I think it’s just a bearing, but I’m going to try replacing the power supply to make sure. Assuming that doesn’t fix it I will try replacing the Arduino shield. Anyone have any other ideas what it might be or how to go about narrowing down the problem? Thanks!