How to recover the overwriten bootloader?

[lwshang]

Hi there,

My nrf52840 DK seems dead. I want to recover it.

What I did:

1. Put the nrf52840 DK into Bootloader mode by pressing the "IF BOOT/RESET"  button while powering up
2. Drag a hex file (the preflash example from SDK) onto the icon shows BOOTLOADER [I realized that I made mistake here]
3. Then I can't put the board into Bootloader mode anymore. The LED5 no longer blink.

I found this issue: https://devzone.nordicsemi.com/f/nordic-q-a/23125/recover-dk-interface-ic-firmware

That looks very similar to my case. The answer there mentioned: "Flash the bootloader.hex using the SAM3U2C debug pins."

I couldn't find a detailed instruction on how to do that. Could someone guide me? What hardware/software do I need?

Thanks in advance,

lwshang

[Simonr]

Hi

I would suggest you go through this list of some common steps for troubleshooting and recovering your device. The latest  Interface MCU firmware can be downloaded here on our product page.

Bet regards,

Simon