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Prusa I3 Mk2 thermal runaway issues  

alec lavigne
New Member
Prusa I3 Mk2 thermal runaway issues

Hello all, 

After a while of not using my printer I've regained interest and started printing things again. To my dissapointment I've ran into thermal runaway issues. I've tried running the fan speeds at lower speeds but it seems to still fail me quite often. I've replaced my thermistor as I had seen in previous threads that that could be the problem but the problem still persists. I'm running out of ideas and am starting to get quite frustrated. 

I have been able to print a couple of things but the latest print keeps on failing, it's been 4 times now and it keeps happening at the same place. My latest attempt is to lower the fan speeds during bridging as i suspect that might be the issue. That print hasn't finished yet so I can't tell you if that fixed it.

If anyone has any ideas on what the problem could be please let me know.

This topic was modified 1 year ago by alec lavigne
Posted : 01/12/2022 6:09 pm
New Member
RE: Prusa I3 Mk2 thermal runaway issues

Could be several issues:

- Thermistor fault - doesn't have to be the thermistor itself, the cable could be an issue too;

- Heater cartridge fault - if it doesn't heat, it gives an error, don't know if it's the Thermal Runaway one;

- Fan not working properly and thus supplying not enough airflow to cool the heatsink;

- Printing near the limits (bed 125, hotend 300) a little overshoot gives an error.

If none of above work, it might be a faulty motherboard (the most expensive to replace) or some kind of slicer issue. To solve that, we need a 3mf file to check your parameters set.

Posted : 03/01/2023 8:25 am