Thingy91 - can't program, won't go into serial recovery mode, no lights

[Akeem]

I am working on BLE mesh project with Nordic thingy 91 and why trying to understand how to get it working. I previously program NRF52840 on my Nordic Thingy 91 via USB with nRF connect Desktop,

by  -->  switching the SW2 button

     -->  put into MCU boot mode by hold press SW4 while powering on the device.

    --> selecting the device name, add .hex file and write

The programming was successful, but nothing works after. No leds, I cant even switch back to NRf9160 and put it in MCUboot mode or program it.. I try to reprogram nRF52840 with the factory code "thingy91_nrf52_connectivity_bridge_2021-06-28_7a076c22.hex" , the programming was successful but nothing still works . Now I am stuck , i dont know what to do to restore it back to default mode So i can continue with the project.

[helsing]

Hi Akseem,

First, sorry for the late reply.

Which .hex did you program nRF9160 with?

Best regards,

Håkon

[helsing]

Is this the Procedure you followed? 

https://infocenter.nordicsemi.com/topic/ug_thingy91_gsg/UG/thingy91_gsg/updating_fw_usb.html 

Which hw version of Thingy:91 are you using?

Are you able to update the modem fw?

Could you please provide a few screenshots from your attempts to program and from when things are failing?

[Akeem]

Thanks for your reply.. After rigorous check and trial. I got it working to some extent. Now I have the asset tracker NB-IoT firmware working on the nrf9160 and the USB_UART connect running on the nrf52840. But the LED on the board flashes Red at a faster rate compare to the regular blue with a long interval. 

Thanks

Akeem

[Akeem]

Thanks for the suggestion. I use hw version 1.4.0 nordic thingy 91 I was able to get it working now, though i was following the link you provided but wasnt working but i get it working using west flash as described here

https://devzone.nordicsemi.com/nordic/cellular-iot-guides/b/getting-started-cellular/posts/thingy91_2d00_fw_2d00_update_2d00_mcuboot

Now i have it working fine. just had my led flashing RED and frequent as oppose to the usual BLUE and interval.. Thanks

[helsing]

Great to hear you got it working, and thank you for posting the link. 

The various colors for asset_tracker on Thingy:91 can be interpreted according to the table in the descriptuo

Please see the description of the user interface for asset_tracker regarding the colors of the RGB. Red indicates "Error". Is your Thingy:91 still flashing red?

Have you tried the testing procedure for asset_tracker?

"7.c. If association is successful, the device reconnects to nRF Connect for Cloud. If the LED(s) indicate an error, check the details of the error in the terminal window. The device must be power-cycled to restart the association procedure."

Are you able to see anything in the terminal?