Heatbed thermistor gone all of a sudden..?
Hello,
I was being happy making some long prints go by, but after the last print as I prepared to go for another one I got a preheat error.
I am using Prusa Firmware 3.0.11 RC1.
Selftest says that the thermistor is not connected. I have tried reconnecting it several times, no dice. Cable looks healthy, thermistor is in place.
Bed is heating, the LED is bright red. Temperature doesn't change.
Temeprature DOES fluctuate between 27-31 though.
What has happened..?
Re: Heatbed thermistor gone all of a sudden..?
What happens if you go back to 3.0.10?
I had preheat error and support told me to re-flash 3.0.10. My issue disappeared.
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Gert
Re: Heatbed thermistor gone all of a sudden..?
I went back to 3.0.10 and nothing changed.
this is my bed heat pattern, have I ruined it somehow?
Re: Heatbed thermistor gone all of a sudden..?
WARNING - GRAPHIC IMAGES
As I realized I have messed the bed up myself beyond warranty by cutting some traces up, I got nothing else left than to McGyver the living ... out of it.
Cut away a part of the PEI to discover the traces I cut.
Reflown them with a bit of solder. (also reflown some more of them, but only took this photo.. later on smoothed the solder joints with a heat gun)
Added some heavy duty 250'C epoxy putty.
Boom 50/50'C.
Just need to sand the epoxy now. 
Re: Heatbed thermistor gone all of a sudden..?
wow, amazing.
Dont remove the prints with the chainsaw next time 🙂
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Gert
Re: Heatbed thermistor gone all of a sudden..?
It actually was just a sharp knife from another printer, which uses a very thick PEI plate.. 🙂
Re: Heatbed thermistor gone all of a sudden..?
Found 4 more damages after realizing that bottom half of the "circle" doesn't heat..
Oooops.. 😳
Heats like original now. After sanding is smooth and sticks the same. 🙂