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My two prusa printers i3 MK/S have print errors !  

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My two prusa printers i3 MK/S have print errors !

We have buy TWO prusa i3 MK3/S (kit assembly). First weeks, everything ok, prints are well (big prints) but since few days, the TWO printers stop printing ! Sometimes with an error message like "preheat error" or "thermal runway" and sometimes with no message at all, just stopping or printing in empty and sometimes print to quickly, bug and stop. For information, the printers aren't in the same local. 

We have testing a lot of thing for fix this issues :
update firmware
change slicer software for make new gcode file
analysing stl file with mixmesher
clean extruder
change filament
verifing thermistor cable
re-calibrate all
change original sd card by an new speed sd card
change fan speed

How is it possible that both printers have sames issues and how can we fix it ?

Thank you in advance,


This topic was modified 3 years ago 2 times by Elicara
Posted : 07/05/2019 12:41 pm
Illustrious Member
RE: My two prusa printers i3 MK/S have print errors !

To reduce sources of error:

Are you printing from the SD card or via an external device?   

If using Octoprint or similar controller, try printing from the SD card slot on the printer.   

Try printing one of the gcode files sample prints from the SD card.

If you can get a good print with the internal SD card, and a Prusa sample file, then the issue is with your controller.

Posted : 07/05/2019 5:34 pm
Eminent Member
RE: My two prusa printers i3 MK/S have print errors !

I currently also had a problem with "bed preheat error" when printing ABS.

My problem is most likely related to a bug in the current Firmware 3.7.0. There were a few attempts to fix related problems recently.

I checked the source on github: On 10th of April someone commited a premature fix - and the code there makes sense to me (as far as I understood it stops doing the preheat-check when the temperature is in range of the target temperature minus 5°C for hysteresis)

So I'd expect a working update soon.

Until then my workaround to avoid "bed preheat error" is to set only one temperature in the slicer (first layer temperature = same temperature as other layers). With that I just printed the fan shroud that repeatedly failed on me before.

Your problem may be different - better check cables, sensors, ...

Posted : 07/05/2019 7:31 pm