Debug Out port on nRF9160-DK not working anymore

[flau]

Hi All,

I have a couple of nRF9160-DK which I use to program custom boards through the Debug Out port.  Both DK work perfectly well until now.  One of them can't program custom board anymore.  Firmware always goes to the on-board nRF9160 instead of going out to the custom board.  I have checked all DK settings between the two DK and they are identical.  The 10-pin cable is fine.  What could be the problem here?  Any chance the firmware in the Interface MCU needs to be reflashed?

[SwRa]

Hi Floyd,

In that case, the DK is the older one. There's a first stage bootloader inside the chip which will get overwritten when trying to program it and hence chances to brick the DK is extremely high. You can find the JLink firmware,JLink_OB_K22_NordicSemi.bin, in C:\Program Files\SEGGER\JLink\Firmwares. It is not possible to write the binary directly to the chip.. you will need to do this through JLink Commander or similar tools, provided that the bootloader is intact. It is hence not recommended to reflash it.

Regards,

Swathy