Question: iphone 7 plus wont power on
I'm repairing a phone and it won't turn on. Customer gave me phone saying it wouldn't power on and screen needed repairing. Replaced screen with known working screen, also have replaced battery and charge port but still won't power on. Can't get it to be seen by my PC in iTunes either, have tried all reset procedures, any ideas please? Thanks!
iPhone 7 Plus, iOS 11.2