I had that on an E75 after I dropped it.
I was lucky and it is just a loose connection. In that case, watching the youtube video mentioned above will help you readjust the ribbon cable. Be extra carefull when you push back against the back of the screen to separate it from the phone housing.

I had that on an N9 with a replacement screen I bought off ebay, and unfortunately I had to order another replacement screen

So I hope you are lucky in this case!