https://devzone.nordicsemi.com/f/nordic-q-a/74563/how-to-recover-the-overwriten-bootloaderHi there, My nrf52840 DK seems dead. I want to recover it. What I did: Put the nrf52840 DK into Bootloader mode by pressing the &quot;IF BOOT/RESET&quot; button while powering up Drag a hex file (the preflash example from SDK) onto the icon shows BOOTLOADERen-USTelligent Community 13Thu, 29 Apr 2021 11:59:59 GMThttps://devzone.nordicsemi.com/thread/307464?ContentTypeID=1Thu, 29 Apr 2021 11:59:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e6686736-76c3-4cc3-a698-645e4ac65054Simonr<p>Hi</p> <p>I would suggest you go through<a href="https://devzone.nordicsemi.com/f/nordic-q-a/24592/my-nrf52-nrf51-dk-kit-doesn-t-work"> this list</a> of some common steps for troubleshooting and recovering your device. The latest&nbsp; Interface MCU firmware can be downloaded <a href="https://www.nordicsemi.com/Software-and-tools/Development-Kits/nRF52840-DK/Download#infotabs">here on our product page.</a></p> <p>Bet regards,</p> <p>Simon</p><div style="clear:both;"></div>