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Essues after 3.12.2 firmware update  

JeRusPunk Punk
New Member
Essues after 3.12.2 firmware update

Hi guys.I have a Prusa MK3S+ with a Bondtech LGX shortcut Mosquito extruder. Until yesterday, I was printing without any problems using the 3.11.0 firmware version and Build 5471 from Bondtech. Yesterday, I saw an update available in Prusa Slicer and updated to version 2.5.1 and Prusa firmware 3.12.2 and Bondtech Build 6242. The updates went smoothly without any issues. Immediately after the update, I started a new print and encountered an extrusion problem. The filament is being fed, but it's so slow that it sticks to the nozzle and almost nothing is left on the print bed. Even when I try to calibrate the first layer, it's not possible to print anything. It seems like there's a problem with the filament feed, as if the hotend is clogged. Initially, I thought it was clogged, so I disassembled and cleaned everything and replaced the nozzle with a new original one from Bondtech. I reassembled everything, but the problem remained. Then I realized that the firmware may have affected the extruder calibration, so I reverted to the old versions that were working fine (3.11.0 and Build 5471), but the problem still persists. I suspect that the firmware somehow affected the extruder calibration. Can someone help me with this problem?

Posted : 18/03/2023 9:57 am
Extra Fox
Estimable Member
RE: Essues after 3.12.2 firmware update

I'd recommend just re-flashing the 3.11 firmware.

3.12.x has been highly problematic for a lot of folks and unfortunately, there seems to be little commentary from Prusa about what's going on and why.


Posted : 18/03/2023 7:08 pm
JeRusPunk Punk
New Member
Topic starter answered:


I wrote earlier that I reverted to firmware version 3.11.0, but it didn't solve the problem. Although I don't understand why, it just doesn't make sense, but the problem remained. I reached out to Prusa technical support and they advised me to adjust the flow in two ways: through Prusaslicer or Pronterface. The biggest problem was that I couldn't adjust the height of the first layer due to very weak flow. I had to lower the nozzle so low that it almost touched the printing surface. In the end, I used both options. I set the flow in Pronterface to 240 and adjusted the height of the first layer. And then in Prusaslicer, I adjusted the extrusion multiplier for individual profiles. For PETG, it was around 2.9 and for TPU, it was about 3.2, but this is not final yet. I also had to change the flow script at the beginning of the print from E12.5 to E40 because the filament leaked from the hotend during heating, and with the original value before printing, the filament did not come out at all, it only started after the first layer was printed, which ruined it. I spent 2 days solving this problem! And who knows how much more time it will take for the rest of the settings... It was a big mistake to update this damn firmware! You'll be smarter if everything works well, better not to change anything...

This post was modified 3 days ago by JeRusPunk Punk
Posted : 18/03/2023 8:59 pm