Missing Softdevice after cold Temperature Test of 100 hours.

[[email protected]]

Hi,

I am using nRF52805 microcontroller in our product, that need to pass some tests, one of them is Low Temperature Test, We flashed softdevice and application code and sent it for cold Temperature Test.
And we observed these below points after test.

1. Device was dead and not advertising.
2. By reading its memory using nrf connect(J-Link), found application code was missing(only softdevice was present) and device is not advertising.
3. Again, I flashed softdevice and application code now device got working as before.

Specification of Test:

1. Temperature  :       -15 degree Celsius.
2. Duration        :        100 hrs operational.

Kindly, Let me know the possible reason for that and how to fix it for future. Here, I am sharing the snippet of memory read from dead device.

[Kenneth]

Hello,

I checked with our QA department to check if this is something they have seen before, and this is not something they have seen before. 

It's the same flash block that hold both the applicaiton and softdevice, so there are conseptually no reason why one should be contained while the other is erased. I think the problem is related to the application was not programmed and verified before temperature test. I suggest to program, verify, do a hard reset to exit debug mode, do a functional test, and then repeat the temperature test.

Best regards,
Kenneth