After DFU process, nRF52 error

[Rita]

Hello all,

We got the fail situation and we tried to find the solution to fix it.

Our develop situation : 

nrf52832/SDK 12.2.0/Windows

Our products already went to mass production steps and we can use buttonless DFU fuction to update our FW.(application)

But a few days ago, our customer  tried to use DFU app to update their FW(application).

They updated three pieces, and then found two piesces are ok and one is fail.

The fail piece is got the success message after DFU update but  it can't work anymore.

They put the fail piece to us and we fould the strange situation.

First we check the current is normal or not. It seems correct. 

And we tried to download the original FW by J-link directly. It seems incorrect now. It can't work normally.

Do you have any suggestion to analyze the fail piece?

We already use the DFU process a long time, and this is the first time to meet this situation.

Thanks!!

[run_ar]

Hi,

Assuming you are using a custom application for this. Can you check if you still see the device in DFU mode if you use another application such as nRF connect?

Please also check the state of the battery.

[Rita]

Thanks for your suggestion.

If I download the softdevice+bootloader in this fail piece, I can see the DFUTARG device and upload application successfully. But it still can't work normally. I am very confused if I direct dowload softdevice+application+bootloader in another piece, it can work well. But now I download the same FW to the fail piece, it can't work correctly. I also try to download another example FW, it seems working well. How could this happen and how to solve the situation? Thanks!  

[run_ar]

Is the bootloader present when you download the other example fw that works? do you have any debug information from the bootloader and the application?

[Rita]

Thanks for your kind suggestion. I follow your suggestion and finally find out the reason, It should be something wrong in our application. Thanks you very much again.

[run_ar]

Glad to hear you figured out what was wrong.