Bambu Lab HMS error code 0700-7000-0002-0002 is an AMS filament unload failure within the 0700-7000 filament management subgroup. Suffix 0002-0002 indicates that the reverse operation — pulling filament back from the toolhead into the AMS — did not complete successfully.

What the Error Means

Filament unloading requires the toolhead to heat, retract the filament through the Bowden path, and confirm the filament has fully returned to the AMS. An unload failure can occur if the filament tip has formed a blob or mushroom at the nozzle that is too large to pass back through the heat break, if the filament snapped during retraction leaving a stub in the hotend, or if the AMS motor cannot pull the filament back against resistance in the Bowden path. A blob-tipped filament is the most common cause.

Step-by-Step Fix

1. Do not power off the printer mid-unload — the nozzle may be at temperature and the filament partially retracted.
2. From the printer’s manual control menu, attempt to push the filament forward by 5–10 mm to free any stuck tip from the heat break, then retry the unload.
3. If the filament will not advance, heat the nozzle to 15 °C above normal printing temperature to soften any blob that has formed.
4. Attempt the unload again at the elevated temperature. A well-heated blob often passes back through the heat break when pulled with sufficient tension.
5. If the filament snapped in the hotend, you will need to perform a cold pull or use a thin wire to push the stub through and out.
6. After clearing the hotend, load a fresh length of filament to confirm the path is clear before loading a new spool.
7. To prevent future blob formation, ensure the nozzle temperature is in the correct range during filament changes and do not interrupt changes mid-cycle.

Parts Required

• No replacement parts are typically required for blob-related unload failures — basic tools only

Contact Bambu Lab support if unload failures occur consistently with correctly sliced files and normal temperature settings.