When ever I turned my pc it works for a few mins then it crashes and goes to black screen and the gpu flashes white for a little bit and then turns normal I have a 99-A mother board and a cooler master 750m psu here is a vid
https://youtu.be/eI8dJVvlB50 (Sorry for the bad quality)
https://youtu.be/eI8dJVvlB50 (Sorry for the bad quality)