Hey everyone,
I wanted to share something weird that happened with my Bambu Lab A1 in case it helps someone else.
I was printing a tall model, close to the printer’s max height (around 251 mm), and the print just stopped. No error, no pause message, nothing, it just froze mid-print like it thought it was finished.
I figured maybe it was the file or the model, so I tried a completely different print. That one didn’t even make it past the first layer before it stopped the same way. No warnings, no obvious issues, and the printer looked totally normal otherwise.
What my setup looked like at the time
I had rolled back the firmware because my camera wasn’t working properly on the newest version.
Printer was running in cloud mode, connected over Wi-Fi.
I hadn’t reformatted the SD card since I bought the printer (about 3 months).
Mechanically everything was fine, no clogs, jams, or tangles.
When I checked the SD card on my computer, it actually showed up as corrupted and unreadable, which made me think that might be part of the problem.
What I did to fix it
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I tried updating the firmware again, but it got stuck at 32 % during download.
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I powered it off safely (it was still downloading, not installing).
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Pulled the SD card, did a full format on my PC (not quick format, FAT32).
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Put it back in the printer, it now showed 0 GB used / 29 GB total, which meant it was finally clean.
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Ran the firmware update again directly from the printer, and this time it installed perfectly.
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Did a test print, which ran all the way through with no issues.
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Finally, I switched the printer to LAN-only mode so it only talks to Bambu Studio over my Wi-Fi and not through the cloud.
Results
Everything’s been working great since then, no random stops, no freezes. I can’t say for sure what the root cause was, but my best guess is that the firmware rollback + corrupted SD card created some kind of instability, maybe during file reads or network checks.
Takeaways
If your A1 suddenly starts stopping mid-print without any warnings:
Reformat or replace your SD card (FAT32, full format).
Update to the latest firmware directly from the printer.
Try running in LAN-only mode to remove any cloud connection issues.
I didn’t technically “fix” anything specific, I just rebuilt the environment, but that seems to have solved it.
Hope this helps someone avoid the same headache!