This particular connector must be seated all the way, for the screen to work and it's not easy to get it back in all the way. Be sure to note how far in it is, before removing it.

I found removing the back to be very difficult and had to use a mini screwdriver to complete it. While removing the back to replace the clickwheel, I not only destroyed the back, I inadvertently mangled the video cable and so I then had to replace that too.