ebb36 1.2 heater always on
My printer was disassembled for a long time. On reassembly I note that on poweron the hotend heater activates. By the time the pi has booted klipper shurs everythinf down at a hotend temperature of about 340C. The smoke suggests that is a real temperature too.
It used not do this. Any ideas?
4 Replies
Remove the heater from the Board, Power on the Board and check the heater Port with a Multimeter.
Disable the heater in your printer.cfg, is it still on? Check with Multimeter.
On power-on, the heater port develops 24V across it. Disabling the heater in the printer.cfg makes no difference. It looks like the heater mosfet has failed - with power off there is still very little resistance between from 24V supply + to +ve heater pin, and from 0v heater pin to supply -
Specifically, with +ve probe side on heater ground it is 2.4 ohms to supply ground. With +ve probe side on 24v+ there is <1 ohm to heater +ve terminal. This is with power off
I would agree, sounds like the fet failed
yah sounds like time for a new one :/