Chosen Solution

Hey guys, I charged my iPhone 6 and removed at night, in the morning it doesn’t turn on, i tried hard reset but it doesn’t want to work, it had no display but the backlight is on, so i disconnected the battery adapter and reconnected it, and the problem was gone for About 2 months, but it decided to return, the iphone didn’t fell or was damaged by water, and i tried my first solution about the battery adapter, but the apple logo appears for 4 seconds before fading away into darkness, can anybody tell me what’s the problem ?

Yes the problem is you have long screw damage. When you changed the screen you most likely got the screws mixed up. This will be a costly repair, that is if you can find a repairer to do it.