J-link communication timed out

[puchuan]

I have nRF52 Development Kit,after my first time programming the Firmware to my board.I can't erase or program it any more? The nRF52 Development Kit can be connected with J-link,but when I want to read or write any thing from the Kit,It restarts over.Everytimes,It's happenedto me. Is there anyone can help me ?

[Hung Bui]

@puchuan: You mean you have managed to flash the chip only once ? Have you tried to open the board using nRFGo Studio application ? Please make sure the board is powered properly. Do you see a new hard driver added to your computer when you plug the cable in ?

[Hung Bui]

@puchuan: Could you try on the USB port on the back of the computer (the one on the mainboard). Also please try to use a short USB cable. You can try to test on another computer also.

Which firmware did you flash on your board before it stopped working ? Could you check if the firmware is running when you plug the board in ?

You mentioned you used a multimeter to check, have you checked on the pads on the chip ? or just the header on the sides ? I suspect there could be something wrong on the track or on the nRF current measurement header (check the SB9 solder bridge)