Recover Thingy91x if USB not responding.

[NormisL4]

Hi!

It seems that I may have uploaded a non-working application to the Thingy91x. Therefore Device is not conectable via USB.

The device is responding only in "MCUBOOT" mode (by holding button 2 when powering on).

This is what I get in MCUBOOT mode.
 

nrfutil device list
1E462C2EBDXXXXXX
Product         MCUBOOT
Ports           COM7
Traits          nordicUsb, usb, serialPorts, mcuBoot, modem

If I'm trying to flash it with the provided thingy91x_hello.nrfcloud.com_v2.0.1.zip package in https://nsscprodmedia.blob.core.windows.net/prod/software-and-other-downloads/dev-kits/thingy91-x/application-firmware/thingy91x_mfw-2.0.2_sdk-2.9.0-preview.zip Error is returned:

 (McubootInvalid). Message: Failed, Error when programming through MCUBoot: Unable to program multi-image file from file '...\img_fota_dfu_zip\thingy91x_hello.nrfcloud.com_v2.0.1.zip'. Error code: 602 (Invalid).

If I'm flashing the thingy91x_at_client_2024-12-04_b38d03e9.zip then it uploads on device succesfully, the device reboots, but USB is not connecting. The only indication that device is not completely bricked is always blinking led1.

Another important thing.
There doesn't seem to be an option to flash *.bin or *.hex files directly on the Thingy91x via nrfutil or nrfConnect Programmer because whenever I'm trying to upload hex or bin files it returns an error:

One or more program tasks failed:

* THINGY91X_1E462XXXXX: [mcuBoot] Programming of Thingy91X requires a target when firmware is a hex or bin., code: Argument.

Message: Failed, [mcuBoot] Programming of Thingy91X requires a target when firmware is a hex or bin.

2025-06-04T17:43:08.113Z ERROR MCUboot DFU failed with error: Error: Failed with exit code 1

According to the https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/app_dev/device_guides/thingy91x/thingy91x_updating_fw_programmer.html it seems that hex files can be uploaded only via "10-pin Serial Wire Debug (SWD) programming cable".


How should I recover the device properly?
Is it doable with USB cable or should I look for the mentioned "10-pin Serial Wire Debug (SWD) programming cable"?

[dejans]

Hi,

It seems that I may have uploaded a non-working application to the Thingy91x. Therefore Device is not conectable via USB.

Which application have you flashed to your Thingy91X device? Was Thingy91X working normally before flashing this unsuitable application?

If I'm trying to flash it with the provided thingy91x_hello.nrfcloud.com_v2.0.1.zip package

How did you try to flash it?

Best regards,
Dejan

[NormisL4]

Thanks @dejans for replying.

Yes the device working before. I was applying apps from quick start and everything worked fine. I managed to send UDP message via cellular network by using AT commands.

Only thing is that device in https://hello.nrfcloud.com/ I received such message:
The fingerprint you have provided is not recognized, and we were unable to identify the device it belongs to.
This didn't bothered me much.


I build my own application in VS code by using nrf Connect SDK 2.8.0. The Board Target was set to thingy91x/nrf9151/ns

As *.bin files and *.hex files didn't worked for me (because of the mentioned 'Thingy91X requires a target when firmware is a hex or bin' Error), I applied dfu_application.zip through nrf Connect for Desktop v5.2.0 Programmer.

I tried to flash the mentioned thingy91x_hello.nrfcloud.com_v2.0.1.zip with these steps:

- Attach device via USB type-c to PC

- Power on device by holding button2 (This is the only method how device is responding)

- nrf Connect for Desktop v5.2.0 Programmer: Clear all files

- nrf Connect for Desktop v5.2.0 Programmer: Add file thingy91x_hello.nrfcloud.com_v2.0.1.zip

- Select "MCUboot" device And write on device.

 

The same Error is returned via this command via USB cable:

nrfutil device program --firmware  thingy91x_hello.nrfcloud.com_v2.0.1.zip --serial-number 1E462C2EXXXXXXX --traits mcuboot --x-family nrf91 --core Application

[NormisL4]

I was able to recover the device by following the guide here https://hello-nrfcloud.github.io/firmware/html/troubleshooting.html#factory-reset-bootloader

Completed the steps:
1.) Downloaded the zip https://github.com/hello-nrfcloud/firmware/releases/download/v2.0.1/connectivity-bridge-v2.0.1-thingy91x-nrf53-dfu.zip

2.) Moved Switch to nRF53

3.) Powered on device by holding button2

4.) Executed command `nrfutil device program --firmware connectivity-bridge-v2.0.1-thingy91x-nrf53-dfu.zip --traits mcuboot`

For those who might me struggling with the same problem in the future my nrfutil version:

nrfutil --version
nrfutil 8.0.0 (54d8087 2025-01-07)
commit-hash: 54d8087a38b73b6e56942fb1b024b62365f06731
commit-date: 2025-01-07
host: x86_64-pc-windows-msvc
build-timestamp: 2025-01-07T14:31:30.208979700Z
classification: nrf-external

I guess this ticket can be considered as solved.