nrf52840-dk not showing up as a USB device and not listed in VSCode Connected Devices

[olalonde]

This is a brand new board nrf52840 development kit. LED5 flashes really quickly. The 4 buttons activate their corresponding LED. I tried using different USB cables. At some point I got a few messages on my macbook that I don't quite recall but it went something like "the segger was not ejected properly" and it kept repeating. But now nothing. lsusb shows nothing as well. Help.

PS: I tried "Power off the kit. Hold down the "IF boot / reset" button, then power on the kit" but it does not appear to do anything.

[olalonde]

I toggled the power switch from vdd to usb and back to vdd and now the board appears to be dead. No LEDs lighting up, etc. I think the board is dead. Weird as it was a brand new board.

[Elfving]

Hi Olivier,

It could be that you've gotten a malfunctioning board, but most likely something happened to the interface MCU. And from how you describe the problem, it sounds like reflashing the interface MCU is what you need. 

What is the revision of of the board you are using? It should say a version on the sticker on top of the board.

Regarding other potential DK issues, going through the list mentioned here is a good idea. Just to mention everything, one should also make sure that the board is switched on (I've seen people forgetting to do that in the past). Try turning it off and on again and see if it wakes up. The other switches have most likely not been touched as the board is brand new, though it might be an idea to still confirm that they are in the default position. And make sure to use the J2 usb, and not J3.

Regards,

Elfving