After battery replacement, black screen, broken wifi cable?Hello! I replaced the battery in my 16gb 3g and in the process of doing so broke the ring in the wifi cable where it is screw...
Answer to: Repace 8GB HD with 16GB HDExactly, and the logic board can be a pain in the butt to change for the unexperienced.
Answer to: Won't turn on after screen was changed.One of the 3 cables probably isn't inserted right. If I remember right, one cable was for the digitizer, other for the lcd, and proximity sensor. My guess would be that the digitizer cable wasn't inserted properly (it pops out easy went re assembling the phone. But you could always try a hard reset home+power for 10 seconds and see if that helps