The buffer (or AMS Hub) is a filament buffer machine connecting the AMS and the printer.
It has a slide, a spring, and a hall sensor. When the AMS pushes the filament into the tool head extruder, the slide will move forward due to the pressure of the filament. The hall sensor can then detect the displacement and location of the slide, and feedback that signal back to the AMS and the printer. If the spring of the buffer gets stuck, it prevents the slider from moving to the far right, which affects the AMS feed.
When you see that the spring of the buffer (or AMS Hub) is stuck, as shown below, please adjust the spring to ensure that the slider moves smoothly from side to side.
Another possible reason is that the filament is tangled or the spool is stuck and causes excessive resistance:
If the error persists after adjusting the spring, please upload the log file and contact the customer support team.
HMS_0700_4000_0002_0004: The filament buffer signal is abnormal, the spring may be stuck or the filament may be tangle.
0700-4000-0002-0004