usi3d

The Bambu firmware update fails or can't be done online (updating from the microSD card)

Guide based on the manufacturer's official documentation; usi3d has not yet verified it on a machine.

Technology: FDM · Brand: Bambu Lab · Symptoms: Problems after a firmware update, The printer shows an error code or message · Updated on 9 October 2026

Symptom

The update download stops or fails, the printer has no internet access to update, you need to go back to an older version, or after connecting an AMS Hub the printer needs an offline update. While updating, the printer refuses new jobs (alerts 0500-4005 or 0500-4007).

Likely causes, from most to least likely

  1. A one-off network download failure.
  2. The printer cannot reach the Bambu Lab cloud (no internet or LAN only mode).
  3. The update package was renamed, unzipped or copied outside the root of the card: the update fails.
  4. The microSD card uses a format the printer cannot read: only FAT32 is supported.
  5. Firmware too old for offline updates: the X1 needs 01.08.02.00, the P1 01.07.00.00 and the A1 01.04.00.00 or later.

Checks to tell which one it is

  • Check the current firmware version on the printer screen.
  • Check that the card is FAT32: Windows formats cards larger than 32 GB as exFAT by default.

Before you start

Before taking anything apart, cleaning or adjusting it, switch the printer off and unplug it, unless a step says otherwise, and do not touch the nozzle, the heater block or the bed until they have cooled down. If in any doubt about electricity, heat or moving parts, stop and ask a professional.

Step-by-step fix

  1. Retry the online update

    Restart the printer and start the update again following the prompts on the screen. Do not switch it off or unplug it while it updates.

    Check: The printer restarts by itself and shows that the update has finished.

    If that does not fix it: Update from the microSD card (next steps).

  2. Prepare the microSD card

    Format the card as FAT32, preferably on the printer itself; everything on it is erased, so copy anything you want to keep first. On the P1, A1 and A2L the card is not hot-swappable: eject it first from Settings → SD Card → Eject.

    Check: The printer reads the card.

    If that does not fix it: Try another microSD card.

  3. Copy the package unchanged

    Download the offline update package for your model from the official Bambu Lab firmware download page and copy it to the root of the card without renaming or unzipping it.

    Check: The file is in the root of the card with its original name.

    If that does not fix it: Download it again in case it was corrupted.

  4. Update offline

    Insert the card into the screen the right way round. On the X1, go to Settings → General → Firmware Version and tap «Update Offline»; on the P1, A1 and A2L, go to Settings → Firmware → Update Offline. Choose the version and wait 10 to 20 minutes without switching the printer off.

    Check: The printer restarts by itself on the new version.

    If that does not fix it: If it fails again, contact Bambu Lab support.

  5. If it is below the minimum version

    If your printer runs firmware older than the minimum needed for offline updates, connect it to the internet once and update online first.

    Check: The offline update option is now available.

    If that does not fix it: Contact Bambu Lab support.

Prevention

  • Never cut the power during an update.
  • Recalibrate the printer after updating: Bambu Lab recommends it after firmware updates or maintenance.
  • If you connect an AMS Hub to a printer that was already on the latest version, update it again from the microSD card.

Still not fixed?

Tell usi3d's AI about your case: choose your printer, describe what you see and add photos if you like. It proposes checks step by step, with their sources.

Tell the AI about your case

Printers it applies to

Bambu Lab's FDM printers: A1, A1 mini, A2L, H2C, H2D, H2D Pro, H2S, P1P, P1S, P2S, X1, X1 Carbon, X1E and X2D.

Official sources

This guide summarises the official documentation linked here:

This guide is general information: usi3d has summarised it from the official documentation linked here, and it may not match your model, its version or its firmware. If in doubt, follow the manual and the support of your printer's manufacturer. You decide what you do with your machine, and working on it may affect its warranty.

Related guides