I can even take a screenshot (Home and Sleep) and download it to iPhoto. It is a black pic...
HELP!!!! PLEASE!!!!
OK, this information might help some of you. My problem is solved. What happened?
I turned on my iPhone by accident during repair. So it was switched on when I reatached all the connectors. My guess is that the display of the iPhone is simly no "plug and play" component that can be attached while the device is running.
As I wrote in my previous postings: the Phone was running after repair, but the display remained dark. Home and Sleep buttons worked and so I waited until the battery was empty and the Phone turned itself off. After that I charged it and then I already saw the "low battery" screen - I never was so happy to see this screen in my life before!
When the iPhone was ready with all the booting it worked perfectly again.
I think I also got a problem with reversing step 6. Tab is open and I tried to get in the ribbon cable. How far back in do I have to push it? There is a white line with an arrow. Is that how far? I tried and tried but can't get it back that far... and now the display remains black. The phoen does sync with iTunes when attached to my Mac - so I guess that I only have a problem with the display.