I just had these issues, turns out the spring was slightly out of shape, catching the inside of the buffer mech. fliped the spring so the damaged end was on the intake side of the buffer. I damaged the spring when I first assembled the AMS (thanks chinglish instructions!)
Thank you for sharing, wish I found your post 4 days ago, would have saved me many hours, but in the end, you made my day sir by sharing this post
This same thing just started happening with my X1C. Filament rolls out, reaches the extruder, the yellow gear turns clockwise for a bit, then reverses, then the AMS pulls the filament back. Repats 3 to 5 times then I get the error message [0701 8007 191218]. I have two AMS units, so I have the 4-to-1 buffer, which has never been apart, although I did recently remove it to clear some filament. There is no extruder clog, and I’ve taken the extruder apart which looks ok (barely any wear). I’ve tried different filaments, slots, and both AMS. Same results each time.
I just tried using the external filament which loads, extrudes, and prints just fine, so I think the extruder and hot end can be excluded as the source of the problem.
UPDATE: Problem solved. When I replaced the AMS buffer, I did not route the tube properly. Instead of routing it underneath the external spool mount AND the connector, I routed it in between them. This little bit of extra friction caused the filament to stop just shy of the extruder gears. I feel like such a newb!
1 Like
I solved the problem with help of posts. It was the spring in the buffer not aligned properly. Go figure. I messed with it with a little fork ptfe remover I downloaded from makerworld, realigning it. Problem solved. Thanx everyone!
I had the same issue. Removing Bambu’s own 4-way splitter solved the problem for me. Always test if you can print with an external filament roll to eliminate the extruder being the issue.
Did this ever get resolved I am having thr same issue and my brand new printer will not print
I bought another AMS and a AMS hub. The hub(4 connections) was causing the error. I put the original AMS for the 1 AMS connection and put a Y splitter on it and no issues at all. So the hub(4 connection) was my issue. I will open a ticket with Bambu for it.
I hope it will help someone, my issue was that the spring in the AMS hub (the part on the back that connects to the AMS) was a bit off, so open the AMS and put in perfectly back did the trick
Tore my whole machine apart twice trying to fix this. It turned out the AMS cable came loose when I moved it… good times!
I was getting this error on an AMS that I just tried installing (my first). I had moved the buffer so that I could put the AMS on the side. I had the buffer mounted ‘vertically’. I mounted it ‘horizontally’, like it would be in the proper location, and it stopped erroring (at least for now).
Thanks to all for the lively conversation. Put me onto the right fix right away. I also have a Bambu Lab 4 way splitter in line and it doesn’t seem to be causing an issue.
New to printing and stupid here. I had exactly the same issues, was going to look into everything posted, take things apart.
It slowly started to fail on 2 different filaments no matter what position I put them in. One spool was a little wonky but it had worked for multiple prints before. In some cases I cleared the error and it finished, others it just kept failing.
I had just replaced a nozzle, thought it was related to that.
I turned the printer to start inspecting and noticed I had shifted the AMS and the tube feeding the extruder was slightly pinched. It was hard to see when I looked initially until I got a good look. Working fine now.
Hope my stupidity might help someone else.
I just got my replacement parts from support after not able to print for weeks with same issue . I did change AMS hum and motor. Sadly still not work, Issue still persisted.
I had exactly same problem after using a printer for a year without any problems.
I cleaned extruder and not helped, so I replaced it and no luck as well, next step was replacing hot end and no luck either, I swapped a magnet in the buffer and no luck either so I replaced it an issue was still there. So last thing to try was to remove Bambu lab 4 in 1 splitter that I used for printing without AMS when I don’t need it, and it worked. I can go back to printing without any problems 
Maybe this will be helpful for someone.
Not sure if this will help anyone. I’ve spent a lot of hours cleaning extruders, looking at magnets, etc. It ended up being the one-way tube coupling getting flipped going from the buffer to the printer. during a service. So…if you’ve taken everything apart, and put it back together not knowing these couplings are directional, that could be the issue.
Hey I am also have same issues with my Brand new printer with first print
Here’s the issue:
- The printer works fine when I bypass the AMS and feed the filament directly.
- However, when using the AMS, I frequently get the error:
“Warning: Extruding filament failed. The extruder might be clogged. [0700-8007 211944]” - I first noticed this error during my initial AMS print. By repeatedly clicking “Retry,” I managed to get through most of the print.
- The error seems to occur during filament changes. On the final layer of my print, retrying didn’t work, and the print failed entirely.
Troubleshooting Steps I’ve Tried So Far:
- Verified the AMS filament path is clear and lubricated.
- Ensured the filament (Elegoo PLA) is dry and of good quality.
- Confirmed the spool rotates freely in the AMS.
- Checked the printer without the AMS – it prints perfectly.
It seems like the AMS struggles with feeding the filament during changes. Has anyone experienced similar issues or knows how to fix this?
I appreciate any tips or advice. Thank you!
1 Like
Has anyone found a solution? everyone claims something different works for them. I’m about to lose my mind, I’ve tried everything. Is there any way to figure out where the error is coming from? There is nothing wrong with the single spool but the ams is pushing and pulling the filament back. I am tired of disassembling and reassembling the device. help
Same issue… started on the first print… it would do a filament switch the new filament would 100% reach the hot end the 5 seconds later retract and so that 3 or 4 times. Butt odd enough enough I rust pressed issue fixed continue printing because I was sick of it and it worked after a day of messing around simply saying I fixed the issue then pressing print again would work 50% but this is still not right AT ALL is it my tension spring or an issue with filament sensor ?!
Damn that was it! Thanks a lot.
I had the same issue too and struggled to find the reason for a few days but for me it was the spring inside the buffer system. Not sure if this is the same problem but hope it helps. There is a bambu lab wiki on it too (HMS_0700-4000-0002-0004: The filament buffer signal is abnormal,the spring may be stuck or the filament may be tangle.)
1 Like
Someone mentioned a spring in the AMS unit being out of wack. Sure enough that is what was wrong with mine.
It’s funny because sometimes it would work if I just kept pushing “retry” and then suddenly it would stop working again during a print. I think the spring would fix itself for a bit. I kept hearing a pop and then suddenly it would work, but didn’t know where the sound was coming from. Anytime I heard that pop it would work for a little bit. Then I’m guessing it would get scrunched up again and stop working during printing.
Anyway, now that I freed it from being out of alignment, it’s working fine.