Video watching results into BSOD

Not long ago I bought a used iPhone 5s, the problem with is that almost every time I try to watch youtube videos or video from my library it turns in to bluescreen and restarts, interestingly enough sometimes in doesnt happen when im doin those exact things but it does happen 100% of the time i try to start watching slo- mo videos. I ve read about the misplaced screws etc, but nothing really gave me the answer. May someone help me?