NRF52832 easily damaged or just locked?

[dimtai]

We are in progrees of developing a wearable device using NRF52832 with BLE. The problem is, we have quite a few chips dead after several times of rewriting. The dead chips can no longer be recognized. This happens randomly, about once a week or so.

Any hints? Thanks in advance, Dimtai 11/9/2018

[Visti Andresen]

What is the symptoms / output from of a dead chip?

Have you tried the --recover option for nrfjprog (in case the chip just had it's protection enabled)

The only things that I could think of that would kill the chip is ESD, excessive write operations to the flash memory or voltages over 3.6V

I have a very abused prototype pcb sitting on my desktop, its a few years old and has been flashed countless times.
(And I doesn't take particularly good care of it with regard to ESD)

The little buggers don't seem to be that easy to kill