If your AMS 2 Pro keeps jamming even after you pull the filament out, there’s almost certainly filament trapped deep inside, around the extruder motor gear. It looks daunting, but you can open it up, clear it and put it back together in under 30 minutes. Here’s how.
The short version
- Usual cause: old, wet or silk filament splitting and getting chewed up inside the unit.
- Where it hides: around the extruder motor gear in the motor block at the back of the internal frame.
- Tools: small hex (Allen) keys, fine tweezers, a straight length of clean filament, a small vacuum.
- Key rule: pull connectors by the plug, never the wires, and only hand-tighten the tiny screws.
Step 1: Empty the AMS and get into it
- Remove all spools and desiccant.
- Pinch and push the rear feed piece out the back.
- Pry out the two rollers (keep the bearings on the ends) to reveal two screws, and undo them.
- Lift the internal frame towards the back, but before it comes free, disconnect the two cables: the white one wiggles out, the black one has a latch to press.
- Vacuum out the loose filament and dust from the shell.
Step 2: Remove the motor block
- Disconnect the motor cables and release the PTFE tubes by pushing the collet in while pulling the tube.
- Undo the three screws holding the motor assembly and ease it out. The three-pin connector only fits one place, so reassembly is foolproof.
- Watch for the small rubber seals on the back. They’re loose and fall off easily; they help keep heat in when the AMS dries filament.
- Undo the two motor screws. The motor, keyed gear and a tiny bearing come out together; set the bearing aside safely.
Step 3: Clear the jam
- Pull out every scrap of filament with fine tweezers, rotating the gear to find more.
- Blow out the channels, then push a straight piece of clean filament through each of the four feed holes to clear them.
- You’ll probably be surprised how much comes out.
Step 4: Put it back together
- Seat the bearing in its shoulder, then fit the motor with its connector facing the four ports, shaft into the bearing.
- Hand-tighten the screws only. The threads are tiny and strip easily.
- Refit the rubber seals following their natural curve, drop the block back in, reconnect everything and refit the frame.
- Click the rollers back in (check the gear sits on the correct side) and refit the rear feed piece.
Troubleshooting
- Won’t power on: a connector isn’t fully seated. They should bite in, sometimes with a click.
- Filament spews everywhere: a PTFE tube wasn’t pushed back in.
- Keeps jamming: replace or dry the problem filament. Old silk PLA was my culprit.
- Feeder units: these can be removed too (two screws each behind the main board) if filament is stuck there.
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