Issue Resolved: AMS Not Recognized + Red Light Errors (P1S)
Just wanted to share my experience in case it helps others.
I ran into two different AMS error scenarios on my P1S:
All 4 red lights double-flashing
3 red lights flashing + 1 solid red light
In both cases, the Bambu Studio software wasn’t recognizing the AMS at all. I tried wiggling the external connectors—no luck.
This issue started after I cleaned the AMS. There was some oil-like liquid inside, so I drained it and did a partial cleanup (around 85%) since I didn’t want to unscrew or disturb the internal gears too much. Unfortunately, the same red light issue persisted.
So I decided to go all-in:
Removed the AMS by unscrewing the two main screws
Carefully disassembled what I could and deep-cleaned everything
Used a toothbrush to clean the board and remove any fine debris
Let everything dry completely
While inspecting the connectors, I noticed one had a black residue on the pins (instead of the usual shiny silver). I cleaned that thoroughly, checked for any physical damage, and reconnected everything.
When I powered it back on:
Initially, only 3 of the 4 lights blinked—the 4th was off, but no error was shown or red light.
After full reassembly and reboot, all 4 lights returned to normal and turned off after a few minutes (which is expected behavior per Bambu Lab’s documentation)
The AMS was now recognized again in the software
Ran a test print, and everything is working perfectly. AMS is communicating properly and feeding filament as expected.
TL;DR:
If your AMS isn’t recognized and you’re seeing red light flashing patterns—fully disassemble and deep-clean it, especially the connectors. Look for any discoloration or residue on the pins. Cleaning that solved the issue for me.
I’ve been having the same issue over the last couple of weeks. I thought maybe it was because my AMS too connected to the x1c was a little too sensitive. So I reinstalled the first generation AMS and I’m still having the same problem, red lights flashing. So I don’t think in my case it’s that anything needs to be cleaned. Considering that it will happen to a brand new ams2. I think it’s a software update issue.
I guess I could also say that it has been pretty warm in the room where I now have my printers. I have not had any issues with my H2D, just my X1C.
So I could definitely see how Maybe humidity or something may have impacted the electronics.
But…
It’s happening to multiple people. So it must be a bigger problem.
Wiggle the cables on all the connections, and I bet they’ll be good again for awhile. I’ve been running that from my AMS fix playbook for a while now. I did move some AMS units to my newer X1C, as I did deem my AMS Hub was probably dying. I do still get the red blinking lights occasionally (I’ve had one instance since my last post in mid June), but so far, wiggle wiggle has fixed things back up.
Same issue here, since two days it started all out of nowhere.
Started with 4 red flashing lights after a failed print. Removed the filament from the tubes and all went white again. After this during the next print, red after starting printing.
I reseated the BUS cable in the AMS and on the AMS motherboard, did the trick for a couple hours.
Now it’s red all the time. I even re-did the reseat for the AMS cables inside the AMS, but no result.
Also did the self-test without AMS, reconnected AMS but no results.
What would be best to continue? Buy replacement AMS cable set and replace the BUS cable? The power cable (2pin) seems to be working fine since there is power being fed to the unit.
I came here because I had the same (12 blinking red lights) issue.
Turned out to be a almost disconnected cable to the AMS unit. Probably didn’t get it pluged in all the way when I installed it.
Any way, all fixed now after reading the posts from other people. If it happens again, I will definitely use the dielectric grease next time around. Thanks to all that posted with the same problem and to the people that solved their problem.
Dielectric Grease BLOCKS electrical signals. Do not put this grease on or around your connectors. Some people for some reason think this helps electrical contact and misuse it all the time.
No, I did not use the dielectric grease, as I know what it is meant to be used with. In your case this means that you had a different issue because the grease will not FIX a bad connection, it will only make a good connection worse. Your issue was something else, maybe just a loose connection. I would suggest cleaning the grease from your connector as soon as possible. if you look at the ad, they say “prevents arcing”. That means it restricts the electric flow.
Thank you! I was having this problem and struggling to work it out. I’d just taken the AMS apart and was careful to plug everything in again when I put it back together so I hadn’t double checked. Did so because of this comment and apparently I wasn’t careful enough. Checking the plugs at the back like in your pic fixed it
I have resolved mine. It was the AMS connector Board. I was able to get it working if I wiggled the 4 pin connector. Changing the 4 pin connector did not improve. Finally changed the AMS connector board and it is fine.
Hi all,
I’m having the same issue with my A1 the AMS lite has the 4 arrows flashing red and will not communicate with printer. I have checked all connections blockages. I raised a ticket with bambu who sent out new circuit board for AMS which arrived in a few days good Comms from them, but when I swapped boards and switched on printer it still had same issue. So I’m at a loose end now , could it be the A1 causing the issue. I would appreciate any help with this.
Thanks in advance
Today all four LED’s of the AMS started to blink RED rapidly 2 times a second, and then a pause, and repeat. I disconnected-connected all the cables that goes from the P1S to the AMS several times, and it didn’t fix it. I’m from Bangladesh, with high air polution. After reading about comunication error, I thought I should use my low powered handheld vaccum cleaner to get any dirt in the AMS ports. And it fixed the problem. This is very very strange, but I thought I should share this incase it helps anyone.
I really wish I could figure out what is going on with my AMS Lite.
I have had it and been using it successfully since Xmas 2024 without issue. Here about 2 weeks ago, I was in the middle of a print and the AMS decided to stop functioning. Went to reseat the cable and found that the plastic sheathes over the pins on the cable were damaged, with the pins slightly bent. Obviously, that was the issue. So, I got a new cable from Bambu and swapped it out yesterday. Go to power the A1 on, and the AMS lights up, 1,2,3,4 lights in sequence, followed by the solid white indicating a roll of filament is loaded, and then about 5 seconds later, the 4 LEDs start flashing red.
I have already checked both AMS ports, as well as taken the board out of the printer to ensure there were no damaged pins. Reassembled everything and still no change.
In my case, this issue has always been the cable between the printer and the AMS Hub, it seems to work itself loose. I’ve now added pushing it in firmly once a week, hasn’t happened since.
I recently added an all-season room to my home and the code calls for AFCI at the breaker box. Have had the flashing red lights intermittently for months. So after reading your post I tried connecting an extension cord to another room in the house that is not on AFCI. I booted up the x1c and voila no flashing red lights. Thanks for your post. I’m not sure I would have figured this one out on my own.
I had the same issue recently.
I plug in the ams and after about 4 seconds all 4 lights start flashing red, no error messages though.
I checked the cables inside the ams; no issue, checked the 6pin connector; no issue, Did a device self-test and then reconnected ams; worked for a few seconds only.
I ended up biting the bullet and unscrewing the entire back panel to check connections there, but as I was removing the final screws I noticed that this cable was loose. It was hard to notice at first because of the spool holder above it, but properly inserting this cable fixed the issue instantly.
(bambu wont let me upload the picture so just look for the ams cable that goes into the printer underneath the spool holder)
