nRF5340 Unsupported Device. The detected device could not be recognized as neither JLink device nor Nordic USB device

[judyo]

Hi community! I have custom boards using nRF5340. A couple boards has suddenly gone bad and unable to be flashed or communicated with after a few reflash cycles.

I've read through tickets with the same issue but unable to get any closure on my case. On the NG board, I tried running >nrfjprog --recover but am getting the error below.
I have no issue running the command on a good board so I don't think it's a problem with the JLINK or my setup.

I've checked for any short but haven't found any. Is it possible that the chip itself has gone bad?

[error] [ Client] - Encountered error -102: Command connect_to_emu_with_snr executed for 310 milliseconds with result -102 ERROR: Unable to connect to a debugger.[error] [ Worker] - An unknown error. ERROR: JLinkARM DLL reported an error. Try again. If error condition ERROR: persists, run the same command again with argument --log, contact Nordic ERROR: Semiconductor and provide the generated log.log file to them. NOTE: For additional output, try running again with logging enabled (--log). NOTE: Any generated log error messages will be displayed.

[Susheel Nuguru]

Hmm, it is hard to say what happened here, as there could be many things. How many of your custom boards are showing this sign?

• Double check the power supply.
• review your hardware schematics and layouts
• check if there are any shorts or other soldering issues
• Remove the chip from the board with issue and try to put it to another working board and see if you still see an issue. 

At this point it points to an issue with the custom board and not the SoC itself. So if you can do some testing and pinpoint it to an issue with the SoC, there is little we can do to assist here.