How to Fix Bricked Flight Controller

It’s possible that you can brick your flight controllers due to human error (where FC doesn’t talk to computer anymore, just timeout or says connection fail). You might still be able to fly using that FC as normal, but there is no way you can connect the board to Cleanflight or Betaflight configurator.

Reasons for Bricked FC

Actually the word “brick” is a wrong choice, you can’t technically brick a flight controller. The issues we have are more like “locking ourselves out”.

95% of the causes are:

  • Flashed wrong firmware target to the flight controller, e.g. flash CC3D firmware to a Naze32 board
  • On some boards where USB port is shared with UART1, and if you disabled MSP Data on UART1, you won’t be able to connect to the computer using USB again; Most modern FC has resolved this issue by separating USB and UART’s by using “USB VCP – virtual com port”

How to Recover Locked Flight Controllers

Solution is simple, short the bootloader pins and re-flash firmware. If it was a Data port settings that causes the flight controller to stop talking to Betaflight/Cleanflight, you will have to erase all settings on the board too.

Some boards might have a “boot” button, some have solder pads, it depends. For example, here are the bootloader pins on the Naze32 you need to short before flashing firmware.

Naze32_bootloader-pin-short

And here are the settings in Betaflight or Cleanflight Firmware Flasher. Here are the steps:

  • Load the correct firmware online
  • Select “Flash on Connect”, if you have trouble with flashing: your FC board will be flashed automatically when you connect it to your computer
  • Select “Full Chip Erase” to erase – it will restore the MSP setting for UART1

cleanflight-flash-firmware-bootloader-shorted-erase-full-ship

After the flash you should be able to connect it to the configurator again.

If you have trouble flashing firmware, play around with the settings, maybe the baud rate is wrong (some boards need 256000), maybe it’s a driver issue.

If this method doesn’t work for you, check with the seller or manufacturer for support. That’s what you are paying them for after all :) Happy flying.

Edit History

  • Aug 2015 – Article created
  • May 2017 – rewritten for all FC rather than just Naze32

10 thoughts on “How to Fix Bricked Flight Controller

  1. Ben

    Another option if you’re having problems with the COM port is to flash the firmware using an ST-LINK USB adapter. If your controller has a connector called SWM, that’s an option. It’ll have 4 pins – 3v 3, ground, SWMIO, and SWCLK.

    You also don’t have to touch the boot pads, which is handy when they aren’t easily accessible.

    With the ST-LINK software, you just need to feed it the .hex file for your particular board.

    Reply
  2. George

    Hi i have a tarrot
    130 i am a newbie and i have disabled the communications port so my board will not talk to clean flight i would be grateful if you have any ideas about the bootloader pins for the button because i can’t find one hope you can help thanks george

    Reply
  3. yann

    hi , i have the same issue with the change of MSP port … but now when i try to flash . my board is not detected by my computer and there is no com port for it.
    need help :(

    Reply
    1. [email protected]

      Hi Oscar

      I had to do this today. There is a special order to make it work.

      Firstly, disconnect the USB from your PC but leave connected to the Naze32. Then short the bootloader pins.

      Whilst keeping the pins shorted, plug the USB into the PC.

      Still with the bootloader pins shorted, in Cleanflight,
      Check the box for no reboot sequence and full chip erase.

      Hold the short on the pins until it has flashed. After, remove the short and disconnect the Naxe32.

      The connect and your board will be OK.

      II had to do this after trying for hours following the incorrect instructions of just shorting the bootloader pins on startup.

      Reply
      1. Matt Hauer

        I did the same on a Naze32 board (Eachine) and it flashed successfully after about 50 tries. In the one “lucky” try, it was when I pulled the USB cable from one physical port to another. It didn’t work (wouldn’t connect) anyway, and I tried for another hour.

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