Maybe it will seems unbelievable, but after an upgrade goes wrong of an mk4, it seems dead...blank screen, some flashes white and black and nothing else.
Trying to resume with the same V31 first and another V31 later it doesn't respond anymore......just brief flashes...it seems not be able to read cd's

The worst thing is that the navi is not mine...it's of a friend and now I feel responsible...what could be happened?
and what could I do to resume it?
I heard many times this situation on mk3 but never on mk4...
Can someone help me?