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Is your micro:bit board in Maintenance mode by mistake? This page should help.

Maintenance mode

If you have a BBC micro:bit, or other Mbed hardware, and it is connecting as a drive called MAINTENANCE instead of MICROBIT, then you are in the maintenance mode provided for updating the DAPLink software (see below).

The way you access maintenance mode is by pluging in your board to your computer's USB port while holding down the reset button. If you are in maintenance mode by mistake, this might be how it happened

Press the button on the board


To leave maintenance mode, unplug the board from USB, make sure the Reset button is not pressed, and plug the board back in.


Plug in board


The board should now show up with the correct name (for example, MICROBIT). If this fails to work, please follow the steps outlined in “Updating your DAPLink firmware” below

What is DAPLink?

DAPlink is the software that runs on the interface chip of an Mbed enabled board. It provides the USB interface that allows you to drag-and-drop binaries onto the target microcontroller.

Updating your DAPLink firmware

Note: Firmware on your micro:bit should be up-to-date. You can find the version in the 'version.txt' file on the micro:bit. The latest release is:

For commercially purchased micro:bits: 0243: Latest version from the DAPLink project, restoring a microbit foundation URL not the previous manufacturer-specific one

For micro:bits from the BBC free drop: 0234: Reject hex files with incorrect vectors or memory layouts 

If your micro:bit will not leave maintenance mode, then you may need to update or replace the firmware on the board by following these steps:

To update the firmware:

  1. Download the newest firmware:
    1. 0234 for UK free-drop micro:bits

      0234_microbit_if.hex (97.0 KB)

    2. 0243 for commercially purchased micro:bits
        Icon 0243_kl26z_microbit_0x8000.hex (267.3 KB)
  2. Unplug the micro:bit.
  3. Press and hold down the reset button next to the USB connector.
  4. The micro:bit will power on. Your computer's file browser will list it as a mass storage device called "MAINTENANCE".
  5. Copy the firmware hex file you downloaded in step 1 to the "MAINTENANCE" device.
  6. Wait until the drive dismounts and the system (orange) LED is flashing continuously.
  7. Unplug the micro:bit and plug in again, and the board should enumerate as a MICROBIT.

Changelog and previous versions


0243: bug fixes over 0241 (

0241-pf: Update the URL so that it doesn't point to, use the newest version of DAPLink as a base

0234: Reject hex files with incorrect vectors or memory layouts 

0231: Automatically run downloaded hex file: (full changelog below)

0230: Don't accept Nordic hex files on the DAPLink drive

0229: change URLs to BBC from

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