Replaced Screen - Won't get signal or connect to Itunes

Hi all, just looking for a bit of help. I have recently had the screen replaced on an Iphone for the digitizer etc to work, but now it turns on and needs syncing to Itunes.

However, it wont connect to Itunes or pick up any signal.

My power button is also stuck so I'm struggling to try and reboot - any ideas of what could be wrong?