nRF52840 DK drive disappears after nrfjprog -

[Richard Adams]

I got the dev board all set up and working - managed to program a few examples flashing LEDs etc….
So then I wanted to do a BLE peripheral beacon example and it told me to program the soft device - I eventually managed to set up and run the nrfjprog tool with what I thought was the correct file. BUT now the dev board is not coming up as a flash drive ….. I am using a Mac with OS-X

[Joakim Jakobsen]

So you flashed the nRF52840-DK with a file that caused it to stop appearing as a flash drive?

Could I ask you what file you downloaded to the board?
Have you tried to recover the device? i.e nrfjprog --recover (ref: nrfjprog commands).

Best regards,
Joakim