Troubleshooting Paperwhite 3 stuck in boot

[frigurt]

Hi all.
I have a strange problem that started yesterday while my kindle was connected to my laptop.
Suddenly it showed a popup with "device error ..." and something about ejecting before unplugging (I didn't even unplug it, maybe cable contact problem).
I waited for about 2 hours but the popup didn't go away and I couldn't do anything. Restarted the kindle and since then it is stuck on the silhouette boot image.

Tried all power button resets (10, 30, 40 seconds) but nothing worked, it always goes back to the boot image with backlight on full power.

Is there anything else that can be done? What might be the cause to that problem? I have no problem with software or hardware technical instructions, so spare me no details on what can be done
Currently I'm leaving it plugged to a wall charger with hope that it will suddenly wake up like in this thread.