Uploaded October 2025 | Updated September 2026, 1 week ago
If your Bambu Lab printer has a broken part cooling fan, and shows the error “0300-3100-0001-0001” or “part cooling fan stopped,” this video explains what causes it and why not to ignore it.
At first, the printer itself showed this error on screen, but nothing appeared inside Bambu Studio, and all my prints came out perfectly fine.
So I ignored it… until I found small pieces of black plastic inside my prints and later on my print bed.
After investigating, I discovered that my part cooling fan had literally exploded inside the housing! The fan was still spinning (or at least felt like it was), but the blades were completely gone.
According to the official Bambu Lab Wiki this error can mean:
- The fan is stuck by debris or filament strings
- The connector is loose
- The fan itself is broken
In my case, the fan motor worked — but the blades disintegrated, probably due to a small piece of filament getting inside.
If you ever see this error, don’t ignore it — check your part cooling fan carefully with good lighting and listen for rattling sounds.
00:00 Intro — The mysterious error
00:17 HMS_0300-3100-001-001
01:04 False alarm?
01:23 No problems with printing
01:46 First signs of a real problem
02:42 Detaching the part cooling fan
04:41 Conclusion
If your Bambu Lab printer has a broken part cooling fan, and shows the error “0300-3100-0001-0001” or “part cooling fan stopped,” this video explains what causes it and why not to ignore it.
At first, the printer itself showed this error on screen, but nothing appeared inside Bambu Studio, and all my prints came out perfectly fine.
So I ignored it… until I found small pieces of black plastic inside my prints and later on my print bed.
After investigating, I discovered that my part cooling fan had literally exploded inside the housing! The fan was still spinning (or at least felt like it was), but the blades were completely gone.
According to the official Bambu Lab Wiki this error can mean:
- The fan is stuck by debris or filament strings
- The connector is loose
- The fan itself is broken
In my case, the fan motor worked — but the blades disintegrated, probably due to a small piece of filament getting inside.
If you ever see this error, don’t ignore it — check your part cooling fan carefully with good lighting and listen for rattling sounds.
00:00 Intro — The mysterious error
00:17 HMS_0300-3100-001-001
01:04 False alarm?
01:23 No problems with printing
01:46 First signs of a real problem
02:42 Detaching the part cooling fan
04:41 Conclusion
