Hi,
I feel myself a bit silly...my nRF52840 board was working the last few weeks nicely, it was visible both in nRFgo and Keil. I had the board some time in button cell battery driven state and the "NRF only" -switch on (not anymore).
Today, the board did not react to connecting USB cable (what happened?).
I found the instructions to press reset button and do power switch off-on. I got the bootloader menu in file manger open and drag-and-dropped file J-Link OB-SAM3U128-V2-NordicSemi 170213.bin (correct?). Things went on, I got the Jlink menu now open in file manager.
But, nRFgo or Keil did not see the board. I restarted the board and my computer, but no change. I can still see the board in file manager and I even tested dropping blinky hex in successfully.
Any idea how to get the board visible again in nRFgo and Keil?