screen not coming on after replacement. I tested both screens first.

I tested the replacement screen and it functioned properly with the device in question. After completing the process of transferring camera, and homebutton between screens neither of them displayed anything once connected. The phone powering on was confirmed by the vibrations. I have tried clearing the charge but it does not work. I have repaired about 100 phones in the last few months alone however I am completely stumped about what is wrong here. The pins on the phone'a logic board are not bent or damaged and nor are they on the cables....