Voxl-Flight adb not working but fastboot works

  • A voxl-flight I have currently is unable to communicate over adb and I've verified my computer works with another voxl. I attempted to use the debug module to follow the directions here: https://docs.modalai.com/unbrick-voxl/ and here https://docs.modalai.com/flash-system-image/. After following the directions to flash the latest system image, it runs without hanging, but when it gets to the step Done flashing all images. Rebooting device in 2 seconds it says rebooting... then never continues. Afterwards adb still never works even after turning fastboot off. The device does show up before flashing in fastboot devices but disappears afterwards

    Any tips on how to fix a voxl-flight that won't let adb work, but flashing with fastboot somewhat works?


  • Dev Team

    Hi Benjamin,

    What you are doing sounds correct. We've had on occasion where ADB drops out during the flashing process, and the work around for that is to immediately turn the fastboot switch OFF after starting the flashing process.

    I don't know if this will help but it might be worth trying, let us know if it doesn't and we can investigate further.

    We can attempt to flash the image piece by piece as well, which I've seen get a device back up and running.

  • I tried immediately turning the fastboot switch OFF after starting the flashing process, but the install.sh still hangs after installing the images.

  • I don't this it's possible to recover this voxl-flight board. The flight controller portion works and the voxl partially works only in fastboot mode. If there's no other solution I think I just need a replacement

  • Dev Team

    Hi @benjamin-linne can you please send an email off to

    contact @ modalai . com

    and we can work on resolving this.


  • Turns out my problem was due to using a 5v 1 amp regulator! I realized my mistake when swapping boards and suddenly a working board stopped working. I guess 1 amp is not enough to completely boot up the voxl.

  • Dev Team

    Thanks for reporting! We definitely recommend a 6A regulator like the APM ships with the boards. The board will typically use <2A but there are transient peaks when frequencies are changed and definitely on boot.

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