My OctPrint and Monoprice Maker Select IIIP (A Wanhao i3 Duplicator Plus clone) were working fine, but suddenly today the hot end won't heat up anymore. I tried disconnecting the OctoPrint USB and resetting the printer power, and it still couldn't heat up the extruder, such as through the filament menu.
But then it got weird.
I left it off for a few hours and turned it on to see if it was getting 12 V to the hot end, and it was heating up again! So I plugged in the OctopPrint and we're back to square one, the extruder has just been cooling down. I know the thermistor is working, because it's accurately following the temp, such as following the cooldown after the heating stopped working again.
Is it possibly I have a dead hot end and for some reason it temporarily started to work again? Maybe an intermittent short?
I guess the next step is to open up the base and look at the connector to the motherboard, and or measure for 12 V