All was working well on my PRUSA MKII until one day the room temperature of both the heat bed and extruder started to read 30 degrees rather than the room temperature of 26 degrees.
If I tried to print at the correct temperature for the media, it would not extrude. By raising the temperature by 10-15 degrees it would print.
I measured the heat bed with an IR thermometer and it confirmed the bed to be about 10 degrees cooler than what was on the display.
Both the heat head and extruder maintained proper temperature during printing.
I checked the connections and they appear to be fine. I tried a new thermistor and it also read 5 degrees high.
Since the issue effects both temperature, I sense it could be something wrong with the board or Firmware.
I reflashed the controller, but that did not eliminate the problem.
Looking at the circuit diagram there is little common to the temperature circuit other than the microprocessor and OVREF.
I also looked to see if there was a G-Code to adjust the thermistor offset. Couldn't find one.
Since it worked before, I don't think it is a firmware configuration issue as the hardware is the same.
Anyone have any idea what has gone wrong?