Hello,
umfortunately, I seem to have bricked my Elonex621EB (EB600EM):
I tried some firmware updates (621eb-fw1028 and COOLER-vfat-eb600em-0203) via SD card, the updates worked and the software was alright. But then I screwed up antried to install kobo-sd-restore-1.8 via SD card, but that seemed to kill my ebook reader

It did not react during the installation progess for at least 30 minutes. Now i can restart the device with the power button / reset button, but then oly the 6 black boxes at the right lower corner appear and that is it. Also, trying to install other firmwares via SD card does not work: I only get the same 6 black boxes.
When I plug in the device via USB to my PC, the internal memory cannot be found.

Did I completely killed it?
Please help!