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Print failing and heating up to 290 C with PLA  

New Member
Print failing and heating up to 290 C with PLA

I am new to 3D printing, but I have had decent luck so far with most of my prints. However, now I am trying to print this (with a .15mm layer height, 20% infill, and a brim):

It has failed several times in similar ways. When I watch it at the beginning of the print, everything seems to be going ok. The nozzle is heating up to 210 or 215 C (I can't remember which). But after a couple of hours, the smoke detector in my enclosure goes off. When I check on it, there are some issues in the print, and the extruder is just sitting there. The nozzle says it is at 290 C (and it is targeting 290 C - the display reads 290/290).

I can't understand why it would ever try to get up to 290 C. The only temperature settings I see in Prusa Slicer are set as follows:


  • First layer: 215 C
  • Other layers: 210 C


  • First layer: 60 C
  • Other layers: 60 C

My MINI+ is up to date with FW, 4.3.4, and I'm using Prusa Slicer 2.4.0. Any ideas?

Posted : 23/01/2022 2:28 am
New Member
Topic starter answered:
RE: Print failing and heating up to 290 C with PLA

I think it's corrupted G-Code. Every time I generate g-code, I save it to a folder on my computer, and then I copy that file over to my USB stick. I just compared the two files, which should have been identical, but they aren't.

There are 6,305 differences between the two files (the files have around 650k lines). The first line that has a difference appears on line 142,114. The original file on my computer has:

G1 X100.759 Y86.775 E.01906

And the file on my USB stick has:

G0 X100.759 Y(6/775 E.01906

Based on other reports of the USB stick that shipped with the Prusa MINI being poor quality, I'm going to switch to a new USB drive.

One thing that isn't clear to me, is when the corruption occurred. I checked a handful of other files that printed successfully (the oldest one has been on the USB drive for about a month, and is twice as large as this one), and they still matched what I had saved on my computer. That leads me to believe that the files are being corrupted when I copy them to the USB drive, rather than after the fact.

I'll probably (1) switch to a new USB drive and (2) start checking hashes after I copy, at least until I build confidence.

Posted : 23/01/2022 6:19 am
RE: Print failing and heating up to 290 C with PLA

the temperature can be changed within gcode file. Open it and look for sequence M104 S290 if it is there. If so the issue is the gcode file.

even an old man can learn new things 🙂
Standard I3 mk3s, FW 3.10.1 RC1, MMU2S, no closed box, Fusion 360, PrusaSlicer, Windows 10
PRUSA MINI FW 4.3.4, Prusa Connect Beta

Posted : 23/01/2022 12:36 pm
Noble Member

If it's not repeatable there may have been a transient glitch on the power while you were copying the file, they do occasionally happen which is why verify commands exist.  If it it recurs it might be a stuck bit on the drive, a dodgy connection in the plug/socket, or a a capacitor going down slowly...

Once could be an unfortunate accident.  Twice and you need to do something.  More frequent than poor quality drives are dirty, or greasy connector pins.


Posted : 23/01/2022 1:52 pm