# Sentinel Drone (VOXL2) initialize error

Source: https://forum.modalai.com/topic/2733/sentinel-drone-voxl2-initialize-error
Category: Development Drones (https://forum.modalai.com/category/44/development-drones)
Tags: sentinel
Posted: 2023-10-09 11:05:54 UTC by inha_baek
Replies: 7 · Views: 1120

## inha_baek · 2023-10-09 11:05:54 UTC

Hello.

We recently conducted tests on your SENTINEL drones and encountered some issues with one of the units. The issues are as follows.

 - When the main power source (Platform Battery) connected with the drone, only the VOXL2 module`s light turned on, but other devices`s led lights remained inactive.
 - We tried to connect the VOXL2`s system with a USB C-type connector, there`s no linking from the VOXL2 module.
 - We followed your provided instructions, attempting to connect it to an UBUNTU PC and using the terminal command "adb devices", but no detection for VOXL2 was registered.

We kindly request your prompt assistance in resolving this issue. Your immediate attention to this matter would be greatly appreciated.

Thanks.

## Reply by tom (ModalAI staff) · 2023-10-09 16:32:13 UTC

@inha_baek What do you see with `lsusb` on your Ubuntu machine with the USB connected + sentinel powered?

## Reply by inha_baek · 2023-10-12 04:28:07 UTC (in reply to tom)

@tom 

![Screenshot from 2023-10-12 13-15-09.png](https://forum.modalai.com/assets/uploads/files/1697084714254-screenshot-from-2023-10-12-13-15-09.png) 

Here is Ubuntu machine`s screenshot. Left one is normal (one of the units that successfully finished initial setting), and a right one is abnormal.

## Reply by tom (ModalAI staff) · 2023-10-12 17:09:04 UTC (in reply to inha_baek)

@inha_baek It appears as thought the voxl2 has entered in to "QDL mode" which means that you will have to follow the unbricking process in order to bring it back to a working state:
https://docs.modalai.com/voxl2-unbricking/#unbricking-your-voxl-2

## Reply by inha_baek · 2023-10-17 06:16:00 UTC (in reply to tom)

@tom 

Thanks for reply.

With your recommendation, we followed that guide (https://docs.modalai.com/voxl2-unbricking/#unbricking-your-voxl-2).
But in Initiate Flash step, we saw this lines in host pc`s terminal.

![Screenshot from 2023-10-17 15-15-23.png](https://forum.modalai.com/assets/uploads/files/1697523337809-screenshot-from-2023-10-17-15-15-23.png) 

Please check this.

## Reply by tom (ModalAI staff) · 2023-10-17 17:03:06 UTC (in reply to inha_baek)

@inha_baek Do you have the SW2 switch flipped and did you use sudo?

Sometime it takes a power cycle and retry to get it going.

## Reply by inha_baek · 2023-10-24 01:17:25 UTC (in reply to tom)

@tom
Of course we did with SW switch flipped and 'sudo'.
Also we retried a lot of times.

And we got same result in every tries.

## Reply by tom (ModalAI staff) · 2023-10-24 17:18:30 UTC (in reply to inha_baek)

@inha_baek If QDL still isn't working I would look into an RMA: https://www.modalai.com/pages/rma