AMS Filament Jams & Loading Failures

"Unable to feed filament into the extruder"

This HMS message (see HMS Error Code Reference) means the AMS pushed filament, but the toolhead's hall sensor never confirmed it arrived. Work through these in order:

1. Check the AMS slot itself — open the lid and confirm the spool spins freely and filament isn't tangled around the spool edge.
2. Inspect the PTFE tube junctions — at both the AMS exit and the toolhead entry, a small gap or a burr on the tube end can snag filament tip.
3. Look for a "birds nest" at the AMS buffer (the small internal spring-loaded buffer that absorbs feed-rate differences) — this is the most common physical jam point and usually visible once you open the AMS top cover.
4. Try manual feed from the touchscreen for that slot — if filament won't advance manually either, the jam is mechanical, not a calibration issue.

Clearing a jam

1. Pause or cancel the current operation from the touchscreen.
2. Open the AMS lid and gently pull the jammed filament back out the way it came in — never pull it forward through the toolhead, which can push the tangle further into the path.
3. Trim the filament tip at a clean angle before reloading; a blunt or frayed tip is a common cause of repeat jams.

Preventing repeat jams

• Keep spools that jammed once dried and stored properly — moisture-softened filament ovals slightly and snags more easily.
• Avoid overfilling a spool beyond its holder's rated width; overhanging loops are a common snag source.
• If one specific slot jams repeatedly and others don't, inspect that slot's rollers for filament dust buildup.

Tip: TPU and PA/PA-CF are best fed direct-to-toolhead rather than through the AMS — see AMS Setup & Filament Loading for which materials to skip the AMS for entirely.