Chosen Solution
A friend came to me with an iPhone 7 Plus that was jammed in a car door. The screen shattered and there was a bend in the phone too. The phone still worked entirely, I could make phone calls, take photos with the forward facing camera. I decided to replace the screen. I have replaced screens in the past but never a 7 Plus. After putting the screen on, it worked. But I found the phone would restart every 1-4 minutes. Boot up time was normal. After a while I realised while using the phone (in home screen) the phone would not restart, but when sitting unused (lock screen) it would. Because it wouldn’t restart when being used, I was able to update the phone to the latest iOS. But still had the problem. While making sure everything was tight I realised again that the phone would not restart while the screen wasn’t attached to the body directly (with still being attached with the cables, not screws and either on the home screen or lock screen) but a soon as I attached the screen to the body (at least clipped it in), it would continue its restart loop. I have read that it had something to do with the digitiser, camera assembly, something near the earpiece of the phone. Is this possible?
Yes, it is possible to have a short on front Camera Flex Cable and it can prevent to power on Device, Reboots or even boot loops. Try to isolate the problem remove camera and home button and connect it one by one to find the problem.
