Hello Nordic team,
We are experiencing an issue on a product using the nRF52840 where the device occasionally enters a state from which it cannot recover without a complete power cycle.
Unfortunately, we have not yet identified the exact sequence of events that causes this state, but we have observed the following behavior consistently across several devices.
- - The application stopped running completely
- - Voltage remains stable at 3.3 V.
- - Constant current consumption at approximately 4 mA.
- - P0.18 is configured as the nRESET pin.
- - Pulling nRESET low and releasing it does not recover the device.
- - J-Link cannot establish a connection to the device while it is in this state.
- - No debug output is available anymore.
- The issue has been observed on multiple devices, not just a single unit.
- The only known recovery method is removing power completely and powering the device again.
While searching DevZone, we found a similar case ("nRF52840 reset failure"; Case ID: 327068). However, the root cause and resolution do not appear to have been published publicly, so we are unsure whether our issue is related to ours..
We are wondering whether this failure mode is already known and whether there are any recommended software or hardware measures to prevent the device from entering this state.
Any suggestions regarding debugging techniques or measurements that could help identify the root cause would be greatly appreciated.
Thank you.