I also have the same problem.
The phone was not wet and didn't fall.
I was using the phone as a GPS and suddenly it started flickering.

When I turn the screen off, it doesn't turn on again.
When I turn on the phone, I sometimes have a flickering image, but most of the time no image at all.
The device works when I use tv-out.

Here is an image of my screen
http://img856.imageshack.us/img856/4127/n900flicker.jpg

Does someone have a fix for this? Or can tell me the cause of this problem?

Thanks in advance.