Recently, the readings of the thermistor on my UMO are limited.
A completely cold printhead will show ~120°C, when heating up this value does not change until the printhead actually reaches ~120°C.
Then the temperature readings seem to be accurate within a margin of error.
This all wouldn't be a problem, if the printer wouldn't abort heating before the printhead reached said thereshold.
Of course the first thought is about a defect component, so I replaced:
I also checked the cables, of course.
On the new arduino I flashed a customized fork of the Marlin firmware available on GitHub, forked from the Marlin_UM_HeatedBedUpgrade branch.
Here's the link to my repo: https://github.com/MarkusA380/Marlin
What could be the problem?