iPhone 7 plus keeps shutting off after screen replacement

"the problem could be the IC cover that is on the LCD ribbon is exposing some of the micro caps which is touching the LCD shield when you install the screen. Those caps ground on the LCD shield causing the LCD display to either shut down, over heat or make the display look like its fading out.

I experienced this recently with two iPhone 7 plus, both same problem with over heating and LCD display fading out randomly after changing the screen with an aftermarket screen. I checked the new aftermarket screen and those caps were exposed and touching the LCD ribbon shield. I taped it off with a small piece of Kapton tape and i have not experienced the problem since."

Just disconnect and reconnect the battery fixed my issues

"Hi guys I just changed the screen and went the person who fixed it for me was not able to solve this problem of turning off by itself it stays for few minutes then boom off on

So I took a seat and started trying some ideas I figured out this way :-D

what you need to do is only going to settings and reset all that’s all guys and now it’s working so fine"

I would try another screen check connections try without proximity front camera plugged in if that doesn’t work try battery if that doesn’t work you may have a board-level Audio IC that is easily damaged in the iPhone 7