Oh-Mann!
Dear OldTurkey, thank your answer information and so... I think it's kind of a drop of a hard stuff do clean that sensor myself. I did some repairing on my iPhone 4s but this seems to be a different level...
Well. Do you know if I can reach that optical unit without disassembling the whole camera?
It's monday morning, bit of rain and grey skies... I don't know if that is the day to start that job.
But I thank you again for your quick answer!
Have a good day und my best regards!
Michael