AMS won't feed past buffer

Bambu Lab AMS Troubleshooting
1

I have an X!C with the AMS. I’ve printed almost problem free for 1100 hours. A few prints ago I got the couldn’t unload, or retract filament, I’m not sure of the wording. I took the AMS apart and found totally intact filament. No breaks, one long filament from the AMS to just above the extruder. I’ve tried every slot, different brands of filament, but the results are the same. I have changed all the PTFE tubes in the AMS and from the buffer to the connector that carries the filament into the printer. I’ve cleaned, compressed air everything, no success.

After all this I took the PTFE tube off where it enters the buffer. I then tried to load filament, multiple slots, and the filament came just to the end of the tube, where it normally would have been just entering the buffer. I cut and inch off the PTFE tube and tried loading the filament. It came to the same spot, exposing an inch of filament. I then tried a shorter piece of tube, and it still ran out the same length of filament. Could the motor in the internal hub of the AMS be overheating? I have noticed when I take the AMS apart to remove the filament, that motor has been very hot. Any help will be appreciated.

2

At this point, I would put in a support ticket. I know that it is painful, but they actually do help if you remember that the person at the other end is also a human and deserves respect.

A few tips, do not demand an instant resolution or go in with an angry tone. Use a formal tone, i.e. say sir or maam or even just Mr. or Ms.in your report. Provide all logs from the printer, get them one at a time, they take forever to load, but uploading more than one at a time makes everything go so much slower. Be patient, they are in a different time zone than you are so replies take time. Also, do whatever test that they request, this helps them to diagnose your problem faster.

3

I opened a ticket before posting here, I just wanted to get as much info for them as I could for the tech when they respond. I did send the log when I opened the ticket. Thanks for your advice