Update: my ICS suddenly turned back to life. after waiting a few hours, keeping it unpowered, the stick somehow forgot it's last settings. now it's booting up again and i have the ability to access the BIOS and all recovery options. Maybe someone else is experiencing this too?
Last action was the change from a 32bit bootloader, to a 64bit fashioned one and the according setting in BIOS.
ok, so this issue is definitely fixed by installing the newest 0030 BIOS. before I was on 0018 BIOS. tried multiple monitors and TVs since the update and the issue is now gone. before, 2 of 5 display units i've tried remained black on powering on the device. maybe this is useful to someone facing the same issues with his ICS.