nRF52840 DK not showing up on PC

[Muqarrab]

Hi,
I have 2 nRF52840 DK but suddenly both are not showing on my PC. I have checked my data cable which is working fine on mobile and transferring data. I have also checked my port which is working fine.

What should I do?

Thanks!

[Vidar Berg]

Could you try see if the board gets detected if  you keep the reset button pressed while powering on the board?

[Muqarrab]

Yes it shows this screen 

[Vidar Berg]

That's a good sign, that means the connection to the PC should be ok. Now, please try program the Jlink FW onto the board. You can download the jlink FW as a bin from the product file here: https://www.nordicsemi.com/Software-and-tools/Development-Kits/nRF52840-DK/Download#infotabs. After you have downloaded it, you can program it onto the board by copying the file to the BOOTLOADER drive.

[Muqarrab]

Thanks, Problem Solved