# Unable to unbrick ModalAI Voxl m500

Source: https://forum.modalai.com/topic/518/unable-to-unbrick-modalai-voxl-m500
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2021-10-26 11:39:37 UTC by ashwin-umdlife
Replies: 6 · Views: 1532

## ashwin-umdlife · 2021-10-26 11:39:37 UTC

Hello there,

One of our ModalAI drones is bricked and we are unable `adb shell` into the device. Following the instruction to unbrick given [here](https://docs.modalai.com/unbrick-voxl/), I am unable to find device upon `sudo fastboot devices`.

Here are the instructions we followed to unbrick the device:
    
* Power off the VOXL
* Detach VOXL USB cable (to ensure USB is not supplying any power VOXL)
* Attach the USB Expander and Debug Add-On board
*  Ensure the FASTBOOT labeled switch is set to on
* Ensure the EMERG BOOT labeled switch is set to off
        NOTE: if your board is missing the EMERG BOOT switch, this is OK as its default un-populated state is OFF
* Power on the VOXL
* Reattach VOXL USB cable
* After VOXL boots up (about 5 seconds), set the FASTBOOT back to off

Here is a video of the attempt https://youtu.be/BDEEefeVZ20

Please let us know if we have missed any steps. Thank you.

Ashwin Sushil

## Reply by modaltb (ModalAI staff) · 2021-10-26 21:50:12 UTC

Hi @ashwin-umdlife ,

Sorry this post is shown as 'deleted' for some reason, testing a response.

## Reply by modaltb (ModalAI staff) · 2021-10-26 22:04:49 UTC

Hi @ashwin-umdlife ,

I un-deleted this post, I'm not sure if you meant to delete but was asked from our contact email to look at this post.

OK, I think we have some timing issues possibly happening here.

Let's work through this and see if we need to update our documentation....  there's a couple scenarios to work through so it's a little tricky.

The idea here is that we want to mimic "holding down the volume-down key while powering on a phone and letting go right after you power on" and then run the command.

So, let's try this:
- have m500 powered off
- have fastboot switch turned ON
- have USB cable connected to m500, not the host (because VOXL can get a little power from USB, but not enough to boot)
- have your terminal open and ready with `sudo fastboot devices` command waiting

Now:
- plug USB power in
- power on m500
- turn fastboot switch off and quickly run the command (hit ENTER on the terminal that has the command waiting)

Repeat this several times if possible.  If we ever detect a device in fastboot mode then we can next attempt to update the system image.

## Reply by ashwin-umdlife · 2021-10-27 12:49:57 UTC

@modaltb I deleted this post because I figure out the usb should be connected to the voxl board and not the expansion board. Thank you making this clear. I see that there is a video made by your team explaining the unbricking procedure. It will be great if you could add it in the office modalai unbricking documentation.

## Reply by Roman Rempel · 2021-10-28 07:08:13 UTC

@modaltb 
Hey!
i also try to unbrick my VOXL
adb - does not work
but the fastboot sees the device
Tell me how to properly flash system image using fastboot

## Reply by Chad Sweet (ModalAI staff) · 2021-10-28 14:19:51 UTC

Can you please see try this post? https://forum.modalai.com/topic/525/voxl-adb-or-wi-fi-no-longer-communicating

## Reply by ashwin-umdlife · 2021-10-28 14:54:20 UTC (in reply to Chad Sweet)

@Chad-Sweet I think we are all commenting on the wrong post here. The issue of this post was solved by connecting to the appropriate usb cable. 

However, @Roman-Rempel  I guess you are having similar problem as in this post https://forum.modalai.com/topic/520/voxl-stuck-in-waiting-after-unbricking/3 ?