I just had my A1 suddenly stop printing. It made a noise and when I looked over it had stopped, the screen and light turned off and the HMS light was out too. Power light at the back stayed on.
After some power cycles the screen was still off. Removed sd card, screen still off.
I put the card back in and left the power on a bit longer and suddenly there are flashes of white light coming from the internal compartment under the screen and I’m hearing electrical noises, possibly out of the speaker, there is no smell of burnt electrical components. Obviously at this point I panic and switch it off.
After collecting myself I decide to pull the power plug out for a minute, then power it back on. Some more brief flashes of light happen and now it powers on normally again and seems to be working… what the hell just happened?
I haven’t tried running a print on it yet, I think I should probably open it up and have a look at the board first, though I’m not sure if I would be able to know if there was an issue visibly.
Do I contact support at this point if it’s working ok?
This really couldn’t have happened at a worse time too, I just had a bunch of orders come in and the printer has been working flawlessly until now!
I’d recommend definitely open a ticket
Initial thought would be to unplug, unscrew the bottom frame, and ensure that the motherboard’s and power supply’s wire harnesses are still firm, and that you do not see any signs of arc flashing. (black char, melted plastic, etc - unlikely but given what you said, safer than sorry) Focus on the ribbon for the display. Visuals here Mainboard Replacement Guide - A1 | Bambu Lab Wiki
Thanks for the reply.
I did open the bottom panel and don’t see any signs of damage, the display ribbon looks fine to me.
I ran the print again after and it finished fine this time. Ultimately very confused about what happened.
I’ll go open a ticket and see what they say though, thanks again
I’m no electrical engineer, but I agree with your assessment on the connectors looking ok.
Out of curiosity, what firmware version are you running?
It’s running on the latest 01.05.00.00
Been printing continuously with no issues since it happened, no response from my ticket to Bambu yet
Bambu responded and basically they’re like 
Since the printer now seems to be working flawlessly I guess it’s understandable. They say as there are no ongoing faults, that the logs won’t show anything, perhaps it was just a momentary power issue and hopefully a once off.
I have had this problem 2 times. It freezed mid print. Nothing I could do to fix it on the spot. I had to turn it off and on again. I searched online and the only thing I could find was a post that said it could be a problem with the network connection. They recommended to print from the SD and not go transfer it from the PC to the printer. But I also use the bambu handy app. So far I haven’t had the problem again. But every time I start a long print, i’m stressfull 
Ah that’s very annoying, I was expecting the A1 to be rock solid and reliable so I wouldn’t have to stress about random failures like this.
Yeah resorting to manual SD card transfers almost sounds worse than the print failures lol.
When my random failure happened I did have the option to resume the print once I pulled the plug and got it to boot back up, I was too freaked out at the time though so I cancelled the print. I seriously thought it was shorting and frying itself the way the lights and the speaker were going off. If it does happen again though I will try that.
Hi, I had exactly the same thing happen, 1 in 1. Is your printer working now? Has anything happened to him?
No problems since, 1500 printing hours. Still couldn’t tell you what the hell caused it though
I believe I can see a failed capacitor in your original picture, I have highlighted the capacitor with a red rectangle in the attached image:
If you look closely you can see that the capacitor appears cracked near the top and there are signs of scorch marks to the right of it. This looks like a high value multi-layer ceramic capacitor. This type of capacitor tends to fail short circuit which can result in high current flow and rapid excessive heating. Given sufficient available energy they can then blow open, much like a fuse, which I guess is what happened here.
I have no idea how important this part is but if you have been successfully printing then its probably not worth worrying about.
Thanks for taking a close look at my board, I still have the uncompressed photos and I think you’re right it does look blown
Like I there have been no further issues but it does bother me that there was an actual hardware failure on a less than month old printer at the time. I think I will contact support and see if they will send out a replacement board while I still have warranty.
Thanks again, I would never have noticed that
Exactly what happened to me today.
I have around 3000 hours print time on it.
I lubricate it everytime it’s asking and cold pulling every other week or so.
It’s standing on a metal rack with thin metal sheet.
Printing as usual, it failed around %70 of the 20 hour print.
The screen is unresponsive. Even though it’s laggy, i could control the light on and off for 2 times. Then machine gone offline.
I also unplugged and plugged it. First, the ams was not recognised immediately, it took 10 mins to make it resume where it left off.
I’ll take a look on the board when it finishes printing to check any visible damage.
I’m also concerned. It’s almost 1 year on this machine.
Did support helped you out?
I’ve been too busy to try getting in contact with support again, still no further issues with the printer though. Did you open your A1 yet and find any blown caps?
I got in touch with support and sent them the photo of what looks like a blown cap on my board and they immediately asked for order number and address so they can send out a new mainboard - so definitely pop open your A1 and see if you can spot any damage before your warranty is up
Thanks, same problem here
can you show us a picture of what that looked like?
The images are in the thread but here is where my failed components are on a zoomed out pic, gives you an idea of how tiny they are. You might want to take a high res photo of your board and zoom in to get a closer look for any damage
Thanks for the advice, I will check
Ladies and Gents
I got the same problem today. On a A1 I bought in March.
I’m going to crack it open later today and do some investigating. I will update.
I’m going to replace all of my caps with Japanese ones. They are known for their high quality.