Weird hotend temperature behavior
Hi everyone, I'm new to this forum. I have an issue with my 2.5S that I was hoping you could help with. When I stopped the printer due to a failing part, I started getting very strange reading on the hotend temperature. The temperature started going down even though it was supposed to be heating up and ultimately gave an error. When I restarted the printer my hotend temperature now will only read half of the room temperature. For example, the bed registers about 26 deg C and all my other printers register the same temperature for the hotend and bed. But the hotend on the prusa is at 13 or 14 deg C, which is about half the room temp. I can't heat it up either, I get a MINTEMP error because the reading wont go up. I thought maybe there was a short in the wires so I unplugged it and it still registers as 13 or 14 deg C. I am used to the reading being zero when the thermistor is unplugged. Is my Rambo board bad?
RE: Weird hotend temperature behavior
Most likely you have broken wires. Especially because you don't see any difference between plugged/unplugged.
If you have a voltmeter, you can measure the resistance of the heater and the thermistor. 0 = shortage, infinite = broken wire. If you don't have this tool, just replace both.
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RE: Weird hotend temperature behavior
thanks for the reply. Wouldn't it register as 0 deg C when it was unplugged? I can turn the printer off and back on and it still reads half the room temperature, and it will go up or down 1 or 2 degree sometimes if the room temp changes, even when the thermistor is unplugged. I would love to change the thermistor out but it is "glued" in with melted filament. I guess I should just rebuild the hotend?