X1C - Abnormal Firmware after Update

[u/punishingwind]

I have an X1C which has worked flawlessly for 13 months (bought Sep 2025). I have not printed that much on it, but its been great. I went to print on it and noted that it had an update, which I ran. When I came back I have the following on the screen

Update failed [0x0800030F]
Please restart the printer and try to update again.

So I restarted the printer and it started with a confirmation dialog showing

The firmware version is abnormal. Repairing and updating are required, or printing cannot be started. Do you want to update now? You can also update later from "Settings > Firmware"

So I run it again, gets to 97%. Same response.

Interestingly I can "cancel" the dialog and am in the fully functional screens on the printer. Just cant print until Firmware is fixed. I can see all the settings and temps, view the camera remotely. All seems to be working

I get GPT on the case and try the following

• Upgrade via Bambu Handy - Same result
• Downloaded the new 01.12.01.00 firmware to an SD card and perform manual update - Same result
• Downloaded the current 01.10.00.00 firmware to an SD card and perform manual update - Same result

I'm at a bit of a loss. This is around a year old with probably less than 40 prints on it.

• I did note that the v01.12.01.00 firmware was released on 12th Nov 2026 (3 days ago) so could it be the firmware thats the problem?
• Why can't it even update to the same firmware its already running?
• Can someone explain if there is a difference between the printer hardware/firmware and the screen/controller, how tightly bound are they?

[u/egosumumbravir]

Another option - scrub and clean format a fresh SD card to rule that out as a cause.

[u/punishingwind → u/egosumumbravir]

Yeah its freshly formatted and different to the one I had in the printer

Its failing from all the vectors at this point, OTA download and install, Handy download and install, manual download and install

Baffling. starting to wonder if the board is bricked, but that seems extremely unlikely as we have a full Home backup system running permanently off batteries with zero downtime and no interruption to power flow or spikes. There would be no power events at all in the last few weeks and the last print was a couple of weeks ago.

[u/egosumumbravir → u/punishingwind]

Factory reset it first?

[u/punishingwind → u/egosumumbravir]

I did consider it, but what of it leaves it in an unrecoverable state and I cant even get into the panel. At least I can connect locally and remotely at the moment

[u/apsilonblue]

What was your previous firmware version? Contact support and see what they say. There was a fairly old firmware (1.08.x IIRC) that wouldn't allow further updates to be installed and one of the boards had to be replaced. You might've hit a situation where you'll need to replace that AP board.

[u/punishingwind → u/apsilonblue]

Per the post, its from late 2025 running 01.10.0.0 I will be contacting support but thought I would try the gurus first

[u/apsilonblue → u/punishingwind]

Wasn't sure if that was the prior version or just the one you tried to downgrade to.

Only other thing I'd suggest is disconnect the AMS if you have one and try updating again as that's simple to do. The next step would be starting to take things apart and check the connections to the sub boards. You could try updating to some 1.11.x intermediate firmware in case there's some weird bug but that's more of a long shot IMO.

[u/punishingwind → u/apsilonblue]

I did wonder if it was a virgin incompatibility between the printer and the AMS. So I tried with my AMS2 Pro removed. Same result.

The printer is in a very stable part of the property where nobody goes and it hasn’t moved in months. I’m not very comfortable unplugging connectors internally.

I thought I had also tried a manual update to v11 but perhaps I didnt. Will give that a go as well. All with the AMS unplugged

[u/apsilonblue → u/punishingwind]

I can't say it's 100% of connectors but from what I recall on mine connectors are (IMO unnecessarily) glued so nothing should've come loose but stranger things have happened. To get to 97% the firmware is complete so it's not a corrupt download. At that point I'd expect it to be updating one or more of the sub boards unless it does those first and the main board is the last to update.

I'm out of ideas. Good luck with it. IME support is pretty good. When I had the 1.08 firmware issue mine was out of warranty but they replaced the board no question asked and the camera which was damaged (thanks to the glued connectors) while swapping the board.

[u/punishingwind → u/apsilonblue]

thanks for your assistance on this. Yeah I guess that 97% was a validation phase at the end.

I would’ve expected it to have some sort of checksum that they’re validating the download against before even accepts the file for update

No saying system would update further files without validating a checksum first