NB-IoT firmware update bricks device

[Ewoud]

I have a Gpy+pytrack, with updated firmware on the pytrack and Gpy, with the firmware update for CAT M1 applied. When applying the NB firmware update using SD card, it got stuck at 6%, just like described on: https://docs.pycom.io/chapter/tutorials/lte/firmware.html. Quoting from this page:
"If the module get's stuck in here for more than 1 minute while upgrading to the NB-IoT firmware, you can cycle power and retry. In this case it is safe."

However, after re-powering, the REPL freezes after ~20 seconds. Before that, I can upload code, change the LED, etc. Also program execution seems to halt after 20 seconds. I can press the reset button for a fresh 20 seconds of action. A freeze is caused instantly if I call: lte = LTE(). Trying to apply the firmware update before the module freezes does not progress further than: <<< Welcome to the SQN3330 firmware updater >>>

I have had the same issue with a Fipy. I managed to do a successful NB update on a different Gpy. I have two more Gpys that I wish to update, but I am not confident at all that it will work.

I want to salvage the bricked modules, please tell me how to flash the Sequans chip in a different way.

[Ewoud]

@xykon I did that more than a week ago, but didn't get a response (PYCSD-271). I figured my chances would be better on the forum, and it turns out they are ;) . You are welcome to help me here or via the support portal, I have no preference in that respect.

[Xykon]

@ewoud Please use https://pycom.io/contact/ (use the "Technical" option) to get in touch with us.