Chosen Solution
My iPhone 7 plus has a cracked screen and very poor battery life so I ordered a replacement screen and battery to repair in my free time. Unfortunately before I got the chance to the screen all of a sudden turned black and subsequently is stuck in a boot loop. I have put it in recovery mode and connected to my Mac and tried to restore and also update it after that restore / update finishes it remains in the boot loop SOMEONE PLZ HELP!!!!
I suspect that the impact that caused your cracked screen caused (directly or indirectly) some logic board damage as well. That is not uncommon and iPhone logic boards in general tend to be very sensitive to flexing. You don’t have to bend the device for the board to flex, it endures micro-flexing just through daily use, especially Plus devices. See the Touch Disease (iPhone 6 Plus) and Audio IC (iPhone 7) debacles for reference. So at this point I believe you have to have this phone looked at by an experienced micro-solderer; they may be able to determine the root cause and repair your device.
I would recommend you to try to put on the new screen and then try to boot again.
