It seems these guys prefer insulting one another rather than learn to solve problems.
First off, no one suggested irecovery? Not that I think this is the problem, but someone should have come up with that one as this looks like it is an auto-boot issue. BUT, it isn't.
You need to look at the cause, and that can only be something from when you had it apart.
Very often this will happen if the flex cable connector on the bottom left, thats #4, is disconnected or loose. Check that connection, if it is slightly off it would cause this. If not, check the rest of the flex cables. It has to be something physical, it would not make any sense and you have gone through the motions regardless. Pop off the screen and double check everything even if u think u didn't touch it, check it.
Wow, newbies around here giving their expert advice, wait newbies can't give expert advice thats an oxymoron...strike that, reverse it!
Let me know when your done restoring my man!
i0nic