Bambu Lab HMS error code 0700-7000-0002-0004 is an AMS filament change failure in the 0700-7000 filament management subgroup. Suffix 0002-0004 indicates that a mid-print filament change sequence — where the AMS unloads one filament and loads another for a different color or material — did not complete successfully.

What the Error Means

A filament change sequence combines both an unload operation and a load operation in sequence. Suffix 0002-0004 represents the overall change operation failing, which could be due to a failed unload (leaving the previous filament stuck), a failed load (the new filament not reaching the toolhead), or a timing failure where one or both sub-operations exceeded their allowed time window. During multi-color printing, these failures are especially impactful because the printer pauses mid-layer waiting for the change to complete.

Step-by-Step Fix

1. When the error appears, note what stage the change reached — whether the old filament was successfully pulled back or whether it is still in the Bowden path.
2. If the previous filament is still in the path, follow the unload error steps from the 0002-0002 guide to clear it before addressing the load.
3. If the new filament failed to load, follow the load error steps from the 0002-0001 guide.
4. Inspect the PTFE tube from the AMS to the toolhead for partial blockage from filament residue — repeated partial changes can leave small material deposits.
5. Confirm the purge tower settings in Bambu Studio are sufficient for the materials being swapped. Insufficient purge can cause the previous color to remain in the nozzle and partially block subsequent loads.
6. Reduce the maximum print speed if frequent change failures occur at high speeds — fast printing leaves less time for the change sequence to complete.
7. After manually clearing the path, resume the print using the print recovery option if available.

Parts Required

• No replacement parts are typically required for change sequence failures — basic tools only
• PTFE tube if internal deposits are found

Contact Bambu Lab support if filament changes consistently fail on a specific slot or with a specific filament type after clearing the path.