I had the same problem. I was playing and it just kept turning off. no light no sound just all of a sudden a black screen and I was cluless. I cannot see how the HDMI could stop post maybe when it's turning on but never stopping it all together. So i waited, I unplugged everything, got a cotton bud and got as much dust out as possible from the intakes and let it stand for a few minutes. It was warm to the touch but nothing worrying. So I turned it on...nothing. I had a radio sitting next to me that ran odd DC and that worked with the power supply so I knew it wasn't that or the socket. So then I went to move the socket and as easy as it could be The PS4 socket was no more than a mm out. So I pushed it in and...boom it worked. So just go through the basics first before you take it down to its individual components.