Hey, is the contact disconnected atm? If you disconnect it and that stops the bootloop then there is a fault in your front camera flex/als/proximity. You need to replace it. It controlls the screens brightnes, the front camera, the function where the screen gets dark when lifting it to your ear in a call, the earspeaker function beacuse that flex is the only thing that connects the earspeaker to the motherboard. When you set the contact down to the motherboard besure that you get it down on both right and left side, sometimes it only gets down on one side.
There is a new homebutton that you can use that has the click function (home) but touch id dosent work, dosent need to change the charging port to use the newest replacing homebutton, just replace the homebutton. If you want touch id to work a part of the flex cable need to be changed (microsolder)
Check so the metal part on the screens flex cables dosent hit the speaker or the motherboard when clicking it back in the housing. If the screen isen't up a bit on the right lower side when its in place test with a small piece of tape on each side of that part on the flex or directly at the speaker/motherboard. I have had the same problem once and then it hit the speaker a bit. so released the plate and moved the flax cables a bit higher
The homebutton and touch id wont work when replacing the homebutton on iphone 7&7+. Test a hardreset (power button and volume down) and if that dosent work test to unplugg the homebutton, and if that dosent help test unplugging the front camera.
It looks like the glas have seperated from the plastic, the screews need to be removed to open it. If the glas gets moved upwards more you may breake something like the homebutton or screen glas.
Im not sure about iphone 6 but i know one iphone 5S that did get reversed problem, no music sound but ear speaker worked. A small metal part did get bended when the battery connector was set down . remove the battery connector and the lightning connector and around that there is smal protecting tape, remove that and look around the battery connector if you see any metal parts or components that are bended/moved or hits any other component.
Hey have you tested a hard reset? Hold power button and home button the same time up to a minute, relese when you see the apple logo. If that dosent work, I would open it up, relse the plate over the connectors for the battery and lightning and look if anything looks damaged on the board
