My X1C, just a few weeks old, suddenly started making a loud and raucous buzzing noise when powered on. I identified this as the MC board fan, and found that if I removed the fan it seemed fine, but even just touching its bracket caused the plastic panel to vibrate noisily.
I see in the Facebook group that I am not the first to have this problem, and some have asked Bambu to replace the fan. If you encounter this problem, try this first. You’ll have to remove the fan - instructions are at Replacing the MC board fan / Main Board Fan | Bambu Lab Wiki
With the fan out, push hard on the fan hub. You may feel it snap farther down on the shaft. If so, replace it in the printer (you’ll need to supply your own double-sticky tape), and the issue should be solved.
Like nearly all electronics makers, Bambu uses the cheapest possible components, and there are a lot of poor-quality fans out there. I’d encourage Bambu to look for a different supplier.
Sadly, the “fix” was temporary, as I worried it might be. I turned the printer on today and the noise returned. I’m in discussion with support now on getting a replacement, though I might try the Noctua as well.
I’ve got the same issue on my printer. The noise originally surfaced after a moved the printer across the room. I can get it to stop by poking and prodding it, but it always comes back. I’ve got two replacement fans on the way. Definitely seems like a higher quality fan supplier is needed.
Got the same issue here, too. The “leave the printer on” solution is undesireable
I’ll give the “push in the hub” solution a try, but I think honestly replacing the fan with a better brand is the way to go.
if I check this picture here taken from the wiki. this fan is not cooling this heating block.
you can see in on this picture here, the fan blow on top and under this block…
It moves some air past the heatsink, and also cools the underside of the board which will reduce the driver temps - the stock fan doesn’t move much air. It would possibly be a problem on a long print with a higher-temp heatbed that elevates the chamber temperature.
I have the Noctua fan on order, will see how it goes.
Got the same issue here, too. The “leave the printer on” solution is undesireable
I’ll give the “push in the hub” solution a try, but I think honestly replacing the fan with a better brand is the way to go.
update: I pushed in the hub, and that seems to have cured the issue for now. Thanks!
So, I too have the noisy MC fan. I stripped it out and tried pushing on the hub. To my surprise it clicked further down… woot woot! re-assemble and cross fingers. Nope still the horrible noise. Stripped it out again and did a better inspection. I peeled the sticker off and found out the click noise it made when I pushed on the fan was the plastic housing behind the shaft cracking. I took a blade and removed the cracked little parts to revel the button end of the shaft. Replaced the sticker, put it back in and she ran with no noise. I could not hear it running at all, quitter then when it was new.
I believe that the end of the shaft was rubbing on the housing the whole time and when I cut it out there was nothing to rub on. This fix may even be possible with out removing the fan. if you can get your finger around the housing and push the fan until it clicks. Then remove the sticker with some tweezers and remove the little broken bits with a blade or tweezers replace the sticker and you should be good to go. Good luck hope this helps
I have the Noctua A4x10. It doesn’t fit in the stock location (it’s slightly too wide). You can trim off the rubber bumpers around the mount holes so it fits a little snugger but it’s still not a perfect fit.
You’ll also need to re-splice the cable using the connector from the stock fan since the Noctua uses a different type from the JST Ph 4 the board uses. You will need to use a multimeter to figure out which cable is which as well since neither the board nor fan are labeled and I’ve yet to find a circuit diagram for it.
i.e. it is by no means a simple swap out for anyone considering it.
The map from OEM wire color > Fan wire color for the MC board fan is:
Dark Gray>Black (GND)
Black>Yellow (+5V)
Light Gray>Green (RPM/Tach)
White>Blue (PWM)
You’ll need to remove the rubber grommets/bumpers from the Noctua and even then it is a tight fit (at least on my X1C, YMMV). You can do the splice on the little extension cable the fan comes with if you prefer, gives you an easier disconnect though you’ll need to tape the excess wiring out of the way obviously.
still the horrible noise. Stripped it out again and did a better inspection. I peeled the sticker off and found out the click noise it made when I pushed on the fan was the plastic housing behind the shaft cracking. I took a blade and removed the cracked little parts to revel the button end of the shaft. Replaced the sticker, put it back in and she ran with no noise. I could not hear it running at all, quitter then when it was new.