Thanks...but I guess I need proffesional help. Didn`t help to remove the power for a longer period. It`s really strange though, cause` I had the same problem 2 years ago. Then I used a Sony Servicecenter, and they said that it could be that the software version was to old(!) or that I had pressed the combination for service mode. They ugraded the software, but I think the whole thing sounds a bit strange...
Well, thanks for your help!