I suspect the EXT_SWCLK/DIO and SH_SWCLK/DIO pins on the SEGGER chips of the PCA10028 were burned.
Is there anyway I can fix it? I have three of them behaving the same way.
I've been using the PCA10028 to debug my external boards via P19 or P20 for years.
However, from time to time, the PCA10028 stops allowing me debugging and programming chips.
When operating normally, on the nRFGo Studio, it shows the target chip which is nRF51822.
When it fails, it only shows the nRF51422 which is the chip on the DK or shows a screen with a "recover" button.
If it fails on P19, I can still use the P20 to debug until the P20 fails.
If both P19 and P20 fails, I can connect the SWDIO and SWCLK to R15 and R16 by cutting SB20 and SB21.
I suspect the Segger chips were burnt.
Is there a way I can fix these boards?
PS. I also have four PCA10028 that won't power up and a preliminary investigation shows the AP7333 was burnt but it won't fix the issue with replacing the LDO.