Powerless phone unless orginal screen is on it.

I have been doing repairs for over 2 years now and every now and then I get a 6 plus in that will not work with any other screen. I put a new screen on it and the phone will not power on or anything. I try another screen and Same problem. I put the original screen on it and the phone works fine. All the screws are the same, the LCD's are tested and work just fine. I am leaning hard towards some type of software error but not for sure. Didn't know if anyone else has had this problem or an idea on how to resolve it.