Hi davidfor,
Thank you very much for your fast reply.
Replacing the internal SD card using factory image successfully unbricked my Aura H2O.
Disassembled my H2O as described in
disassemble kobo aura H2O, and flashed SD card while expanding storage as described in
Glo Memory Upgrade, using dd and gparted. Now it even boots faster since the SD card is now class 10 while the original SD card was class 4
