THERMAL RUNAWAY
Been printing both PLA and ABS recently with great results on MK3S. Then, two issues popped up at the same time.
Issue 1: Thermal Runaway on the hotend,
I replaced the thermistor, checked for loose wires, and still having the Runaway issue. I found in the forum a suggestion to disconnect the power-panic feature from the power supply, but still get the runaway issue. The prints start fine and z-height looks good, but filament comes out inconsistently. Lays down a nice layer of fill, but then stops and starts later. After the second layer starts, thermal runway error happens.
Issue 2: sporadic extrusion of filament. Not sure if related, but both happened at the same time. I did several cold pulls to check for a clogged print head to solve issue 2, and it looks very clean. Tried adjusting the tension on the gears looser and tighter and checked that they are clean. Tried different rolls of PLA. Same issue.
Any chances these are related and any suggestions for troubleshooting?
RE: THERMAL RUNAWAY
For thermal run away, this might caused by an environmental issue (ie: the abient temp of the room is either to high or too low. We would likely need some more information to be able to provide more direction on what could be causing the issue.
I would try disabling the filament sensor and do a manual load of the filament to rule out the sensor. If disabling the sensor fixes the issue i would check the cable to ensure it's plugged snugly, could also be a failed sensor or crack in the cable.
RE: THERMAL RUNAWAY
I have seen it if you plug in the thermistors in the wrong plug. This might be prevented by firmware now.
--------------------
Chuck H
3D Printer Review Blog