MCU failure analysis request

[air]

Hello, I am using nrf51822 / sdk10.0.0 / S110. I write flash in SD / bootloader / application order. I use nRFgoStudio and J-Link. There are about 20% of malfunctioning samples when operating after writing. The malfunction appears to be an MCU halt state. I would like to verify this part and request a failure analysis. I want to know what procedure I can apply for. I also want to know what to prepare.

thanks.

[air]

Frankly, it's not my case. Someone believes so. I understand your answer. thanks.