After 1h of printing with m300 sudden temperature drop error showed up. After that extruder temperature goes to 47% and then drops to ~30% very fast so I thought its thermocouple problem. Replaced heater&thermocouple and that didn’t change a thing. Checked all extruder cables and PCB board and I can’t find anything that could indicate a problem. Any suggestions where to look for a problem? I don’t want to buy more parts that i don’t need…
Make sure that all cables are firmly plugged into the extruder PCB and check if the heater&thermocouple are properly installed and secured in the hotend. However, the extruder cable and PCB may be responsible for the given issue as well. While the printer is heating – you may grab the extruder cable and move it back and forth, reaching the maximal spread. At a specific angle – the cable might start working properly, which would confirm the diagnosis. Still, the extruder cable is a consumable part, so it might be high time you replaced it.
I puled the extruder cable and tensioned it… temperature started to go up and down… its just strange that it kinda works and doesn’t show error. Switched cable ends from extruder to main board and error poped up. Hope changing this cable will solve my problems.