Unable to unbrick ModalAI Voxl m500

[ashwin-umdlife]

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, 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

[modaltb]

Hi @ashwin-umdlife ,

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

[modaltb]

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.

[ashwin-umdlife]

@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.

[Roman Rempel]

@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

[Chad Sweet]

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

[ashwin-umdlife]

@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 ?