Bambu p1s, standard ams. Whatever the latest software is as of 9/16/25.
Since the last update I’ve had AMS comm errors so bad that i had to bypass AMS and go to an external spool. These were never a problem before the last update. As soon as i did that i started having “toolhead fell off” warnings as soon as the tool head starts moving for the print. I check. It hasn’t fallen off. I remove it, reinstall it, restart, and get the fault again. This has to be software related because it consistently does it twice, and only at the beginning of a print, and then never presents the warning again after even a 2 hour print. I also had a few “part fan cooling speed low” cautions but not sure if that’s a software issue or not, as it’s inconsistent.
Am i the only one having these issues?
Im having the same issue, got the ‘upgrade firmware’ on the P1S and AMS about a week ago, and ever since, I get communication errors with the AMS. At first it seemed that I had to power cycle the whole unit in between every print because of it, then I found just unplugging the connection to the AMS from the P1S and popping it back in temporarily fixes it. It also seems to be time based to some extent, I can power cycle the whole unit, and confirm there are no comms issues, but go to start a print 12 hours later and it will have the comms issue again, requiring the power cycle. Im going to attempt a firmware downgrade later and see if that helps at all.
my Printer is on v 01.09.00.00
AMS Hub 00.43
AMS’s 01.06.62
My concern with downgrading, as i understand it, is you won’t be able to update again. Or at least you won’t be notified of updates and be able to click a button to install. You’ll have to load it to an sd card and install manually every time. But maybe I’m wrong.
That is a problem that has been going on for a long time.
As Bambu Labs has improved, changed, fixed issues with firmware updates, as the firmware updates trickle in over time, after every update, there will be a SMALL subset of users that get the toolhead fault, while the majority do the update and have no issues at all. For the great majority of owners, firmware update doesn’t cause any problems.
The only thing I can suggest is if you have made any mods that tap into the P1S power or logic systems of your P1S, try undoing them. Some folks have had issues after using the USB port behind the touchpad as a power source for LED lighting or 3rd party electronics. But not all.
I would check which firmware is on your P1S because currently and which firmware is the most current. I was working on a Raspberry Pi printer project and was on and off BL Github repository a lot over the last week and BL rolled out a firmware which they promptly must have had issues with because a second firmware update was rolled out pretty promptly. A firmware double-tap may mean there was a problem in Update #1, which they quickly fixed with Update #2
Maybe roll back to the most recent update that worked for you and then try and re-update everything. Rolling back will possibly fix issue but is not a viable final solution.
It could just as easily be that the firmware was not written to your hardware correctly and just needs to be reinstalled.
Back when I had a Creality printer running both Marlin and Klipper, it was not unusual to have to write the firmware to the controller more than once.
Do you have anything plugged into the USB port inside of the printer?
I did, a panda touch. I unplugged the usb-c from the back of the touch screen but the usb cord is still plugged in to the printer but not powering anything.
Well, I deleted my comment about the Touch.
I do not know the how or why and it was a bit over a year ago when I plugged in a Panda Touch to my P1S.
I don’t know how but in my instance it seemed like the Touch somehow damaged my first P1S. In my case removing the Touch didn’t fix the problem. It was almost as if the Touch either wrote to the P1S and damaged the P1S programmatically or it damaged the P1S electrically.
I didn’t have the Touch connected and powered up for probably 24 - 34 total hours but in the end I spent a month troubleshooting with BL Tech Support and ended up swapping the printer out for a new one.
This is from the Amazon Touch page. You always want to read the fine print.
Seems like the Touch may even be writing to the controller on the P1S as I believe you would have to write to the controller to give the Touch control of the printer.
- Firmware V1.0.7 Please update the firmware of your panda touch to V1.0.7 for better user experience (download from Github: bigtreetech/PandaTouch/tree/master/Firmware). 2 main new features are added on V1.0.7–1) Skip Objects Support: allow you to skip objects during the print process. 2) Filament drying: add filament drying functionality specifically for P1S. Explore more functions with V1.0.7!
- Compatibility Panda Touch(V1.0.7) is compatible with Bambu-Lab(=BL) printers firmware versions up until: P1P/S>01.07.00.00, A1/A1 Mini>01.04.00.00, X1C>01.08.02.00, X1E>01.01.02.00. Some features of X1C/X1E may be affected by the authorization mechanism of BL, but you can remain them in Lan-developer mode (Check btt wiki web for details). We will monitor all beta firmwares of BL printers and get you informed via our social channel. Warr-anty DOES NOT cover function lost by a firmware update.
I had the same “Toolhead Cover” errors when trying to power anything from that port on a PS1. I haven’t tried powering any from there since. For reference this was on a much earlier firmware version.
Yeah, this seems specifically to do with a ‘since last update’ scenario. And the usb is currently not connected to anything but a cord.
I also know there are numerous people having the same AMS comm errors since last update just like me. Not sure about the toolhead or part cooling fan though.
I dont have anything extra on my P1S like the Biqu Touch, just 4 AMS through the hub.
I’ve just completed the downgrade of the printer to 1.08.02 with the AMS being at the same version as before, and am doing a full calibration and test print to see if the printer downgrade has solved my AMS comms issue. Calibration has another 20 minutes to go, so maybe in an hour I’ll know. If it doesnt work, then I’ll downgrade the printer and AMSs.
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I don’t want to Jinx myself, but so far, no comms issues with my AMS after doing a calibration and two test prints. I’m going to let it stay idle for a while now and then try to re-sync the AMS to confirm that the 1.08 firmware is working, and that the issue is just in the 1.09…
Actually, the problem with downgrading the firmware is that you will be notified that an upgrade is available, every time you turn it on in cloud mode.
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I can confirm i am on 1.09.00 currently
Also weird. Doing a print right now where, for the first time in like 10 prints, no “toolhead fell off” warning. Is bambu AI listening in?
If they are, please get rid of the “part fan low speed” fault, lol.
I’m on my second print, and again no toolhead fault. Are we living in a matrix?
I have 3 P1S and all with 01.09.00.00 version. The issue I am facing is that when the bed comes at the bottom it doesn’t stop and pressures itseld down which makes the stepper motor making grrrr sound. Whenever I do z-axis homing, it goes down and makes the sound. What can be the solution?
There are countless stories on here of problems encountered post upgrade. Updating always carries risk.
If the latest update doesn’t provide a great benefit, or fixes something that I don’t suffer from, then I don’t upgrade.
Right after I did the updates, I was able to print without problems. Then I started getting assorted strange errors, including “toolhead cover fell off” and “part cooling fan speed abnormal”. The most recent failure is that the P1S is now dragging the nozzle directly on the print bed. I have not touched any hardware or changed any settings in the printer or in the slicer. I did raise a support ticket, but got the “there will be a delay because we are understaffed” response.
You have a Panda Touch or Panda Lux installed, or using USB-A port for a power source?