"Err: MAXTEMP: E1" when THERMAL_PROTECTION_HOTENDS is disabled I am trying to port Marlin to my Qidi Tech 1 printer which previously ran Sailfish 7.8. Everything worked fine on the old board, including the temperature sensors.
All cables except for power, LCD, and USB (for flashing) are disconnected. I am still very early on in testing and have yet to plug anything else in.
When uploading Marlin to the board, at first startup I received the following error:
Err: MAXTEMP: E1

PRINTER HALTED
Please Reset

There may be a problem with my configuration. So I commented out all of the thermal runaway protection options since the bed and extruders aren't yet connected:
//#define THERMAL_PROTECTION_HOTENDS
//#define THERMAL_PROTECTION_BED
//#define THERMAL_PROTECTION_CHAMBER

I rebuilt, flashed, reset, and the printer is still telling me that E1 is at MAXTEMP.
Why am I still getting this thermal protection message?
I cleared the EEPROM from the LCD menu in Sailfish before flashing.
This board uses an ATmega2560 and I'm using the default fuses (E:FD, H:D8, L:FF, LOCK:CF).
#define THERMAL_PROTECTION_HOTENDS is for thermal runaway. When the temperature &quot;should&quot; be climbing or falling at a predicable rate, or holding steady once at running temp.
#define HEATER_0_MAXTEMP defines the maximum temperature Marlin will allow the extruder to get to before initiating a shutdown. This is ALWAYS active for an active extruder (E0) This setting is what will throw MAXTEMP if it is exceeded.
MAXTEMP error when there is no heat on is usually from a short in the thermistor cable.