[nRF52 DK] PC does not recognize USB device anymore - LD5 fast blinking

[epetin]

HW: nRF52832 DK, PCA10040 V1.1.0, 2016.23

SDK: nRF5_SDK_15.2.0_9412b96

IDE: Eclipse configured according to https://devzone.nordicsemi.com/tutorials/b/getting-started/posts/development-with-gcc-and-eclipse

SoftDevice: ble_app_bps/pca10040/s132/armgcc

PC: Windows 8.1

nrfjprog version: 9.8.1

JLinkARM.dll version: 6.40

GNU Make 4.2.1 (Built for x86_64-w64-mingw32)

Issue description: after a couple of successful flashes from Eclipse using make, without any configuration changes the board stopped responding. LD5 on the board is blinking very fast. No J-Link devices can be seen in the Windows Device Manager (actually there's not even the category "Ports"), nor using the SEGGER J-Link Configurator:

I have also tried to boot into the "bootloader mode" but it does not change the situation - nothing can be seen on PC.

Does this mean that I need to arrange funeral to my poor Development Kit, or is there still some light at the end of the tunnel?

Thanks!

[brinehart]

I would try plugging in another device such as a phone or tablet and see if it pops up on your desktop. To see if the issue is with the board or the computer. Have you tried reinstalling your USB drivers?

[epetin]

Phone is detected correctly.

Next I tried uninstalling basically everything related to JLink/SEGGER (all USB and Port related stuff from Device Manager (using View->Show hidden devices)). Then reinstalled JLink software (v6.40) and retried (still unknown USB device), ran nRF5x Command Line Tools installer -> Repair -> it seemed to install JLink v6.40 again -> still the same unknown USB device error.