RE: how to recover ATSAM3U2CA-AU(J-link ) nrf52840-dk jlink can't found

Edvin — Wed, 03 Jul 2019 13:28:41 GMT

Hello,

I assume that the power switch on your DK is in the ON position, since you can program it using an external debugger, but can you please also check the following switches:

nRF power source: VDD
VEXT->nRF OFF
TRACE: Def.
SW6: DEFAULT

And also confirm that you have not cut solder bridge SB40 and SB41.

... And confirm that you are using the USB port on the short end of the DK.

If all of the above seems correct, you may have wiped the J-Link chip.

Can you try to hold the IF BOOT/RESET button while you power cycle the DK? Does LED5 start blinking then? If so, then the J-LINK is in bootloader mode, and should appear as BOOTLOADER on your PC. If it does, drag and drop the J-LINK image file into the BOOTLOADER device, and wait until the copy is complete. LED5 should blink a bit faster now. Then power cycle the DK again without holding the IF BOOT/RESET button. Does the device appear on your PC now?

You can download the J-Link image file using this link:

https://devzone.nordicsemi.com/attachment/4a3e5690de3ef14d3d26535d92504257