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Troubleshooting

Start with AFC_BAMBU_UIDS. It lists every unit the BridgeBox sees on the bus and the BridgeBox firmware version, so it tells you straight away whether the problem is between Klipper and the BridgeBox, or between the BridgeBox and the AMS.

Question

AFC_BAMBU_UIDS says the bridge is not connected.

Answer

Klipper can't reach the BridgeBox.

  • On USB, check the cable and that the BridgeBox has power. With serial_port: auto, the chain keeps the board it saved; if you swapped boards, run AFC_BRIDGEBOX_FORGET_BOARD and RESTART.
  • On a second chain with serial_port: auto, make sure each BridgeBox is plugged in. Each chain takes a board no other chain uses.
  • On WiFi, check the address hasn't changed. Give the BridgeBox a fixed DHCP lease in your router.
  • Never list the BridgeBox in an [mcu] section. It is not a Klipper MCU.

Question

The BridgeBox is connected, but a unit is missing.

Answer
  • Check the unit has power. The units are powered by the BridgeBox's 24 V supply.
  • Check the cable from the BridgeBox to the buffer, and between units, is seated. A lit AMS does not prove the bus cable is connected.
  • A unit only claims a bay once AFC's PREP has run after a restart. Give it a few seconds.
  • Run AFC_BRIDGEBOX_BAYS. If every bay of the unit's kind is taken, it waits for one; see No free bay.

Question

My Bambu lanes moved to other lane numbers.

Answer

Lanes move when pool_ams, ams_names, ht_names or lane_base change, or when another unit takes one of their lane numbers. Settle those before the first start. See Lane layout.

Question

A load feeds but never finishes.

Answer

Each AMS feeds until the extruder's toolhead sensor sees filament. Check that the [AFC_extruder] the chain feeds has a working pin_tool_start, or pin_tool_start: buffer with the chain's buffer_type left at bambu. See Extruder.

Question

A spool's tag doesn't read.

Answer

The AMS reads genuine Bambu tags only; an NTAG215 or other third-party tag will not read in a Bambu bay. For a Bambu tag, reseat the spool or run AFC_BAMBU_SCAN LANE=<lane>. An untagged spool still loads and prints; set the lane by hand or pick its spool in Spoolman.

Question

A second unit refuses to start drying.

Answer

One AMS 2 Pro can dry on the BridgeBox's own supply. AFC won't start a second heater on the same supply, because it would reset every unit on the bus. Plug an adapter into one of the units. An AMS HT always needs its own mains cord to heat. See Drying.

Question

An AMS HT refuses to dry with a lane loaded, or an AMS 2 Pro load fails while drying.

Answer

Both are fixed by Bambu's updated AMS firmware. See Updating the AMS units.

Question

I moved a BridgeBox to another printer and it keeps dropping.

Answer

The old printer is still reaching for it at its old address. On the old printer, set the chain to connection: usb or remove its section, then run AFC_BRIDGEBOX_RESET_WIFI on the new printer, or hold the BOOT button for 10 seconds, and set it up again. See Moving to another printer.

Question

The print paused with a BridgeBox link error.

Answer

AFC pauses a print after 5 seconds without hearing from the BridgeBox. Check its power and its USB cable or WiFi signal. Once it is back, the units come back online by themselves and you can resume.

Question

A firmware update failed.

Answer

See What can go wrong. Nothing is erased until the whole image has arrived and checked out, so a failed update leaves the BridgeBox running its old firmware.

Getting help

If you're still stuck, collect ~/printer_data/logs/klippy.log and ~/printer_data/logs/AFC.log and ask on the AFC Discord.