Re: SD2 sudenly stopped heating extruder mid print without warning or kill
Easy way to verify good thermistor or not is to take a hair dryer and blow on the hot end. You should see the temperature go up in repetier-host. If it does, problem is with the heater cartridge. A new heating cartridge (12v) will run you about $8 on amazon, and will include the wiring and everything going all the way back to the boardset. If you really want to make sure the heater cartridge is bad, you can wire it directly to the 12v incoming that goes to your board, then plug it in. The heater will get hot pretty damn fast, so be ready to unplug as soon as you can tell if it's heating up. Polarity doesn't matter.
If the temp doesn't go up, it's a thermistor or thermistor wire. A pack of them is around $10 on ebay, and you can use any wire as long as it can handle the heat. If you want to make sure that it's the thermistor and not the board, you can set your multimeter to resistance and measure across the thermistor. Do the hair dryer trick and you should see the resistance change.
Edit: One common failure point I see for heater cartridges (if they aren't taped properly and secured) is where the wires join the cartridge. There isn't any strain relief there, so if it gets wiggled back and forth too much it will simply snap off. Not much to do at that point except use some high temp solder or replace the cartridge.
can just the heat cartrage be swapped out on the SD2 hot end?
