I recently adquired a Sony Xperia M4 Aqua, and all seems to be alright, it has had no repairs and never been dunked into water before, so a week ago I found that the phone screen had gone black, at simple view you could tell it was on. I pressed the power button a few times and it seemed to lock and unlock, but the screen was black. This made me furious because the phone had not been dropped. After a few minutes of angry mumbling I had the idea of tapping slighlty harder than a simple tap on the screen and it turned on. The touch worked while the screen was black, I was even able to input my security pattern, but the screen was black. After that, my phone has turned on and off a few times, and I have fixed it a few times by tapping on it. What can it be? I would like to repair it, but I also want to know what are the possibilities of it just being a simple loose connector or the screen so I can judge whether I should just buy another phone or if it is worth repairing.
Yes, it is possible that it is loose, however unless you know what you are doing (or are ok with risking doing more damage) I would not open it up yourself. Try a local tech, shouldn't cost much to repair. If they want a lot for it, just get a new phone.