Chosen Solution
I put a new LCD in my IPhone 6S. When I turn it on the lock screen will flash for about a half a second then it will go black. Sometimes it will stay on and the phone will work flawlessly for a few hours then out of no where it will go black again and I wont be able to get it to come back on.
It could be that the drop caused something to break on your logic board, which will act out intermittently. However, it could very well be a bad screen and you need to rule that out first. Do you still have the old screen and was it working ok before replacement? If yes, try it on and see if the issue reappears. If not, you’ll need a new good screen to try it on. Where did you get the first one from?
