Ps4 only turns on with pressure

One day my ps4 made a high pitch noise and switched off while I was in the middle of a game and it use to do this all the time after like an hour, 2 weeks ago it wouldn't come on not even in to safe mode it sometimes worked when I put pressure on the top of the ps4 or when I kept unplugging and plugging back it but then that stopped working and I couldn't get my ps4 on it would just flash the blue light until recently I was told on a page that turn the ps4 upside down and put pressure with your hands where the power supplyand I did so and it worked!! The white light came back but once I released my hand it would go back off in to a black screen then say no signal but the ps4 would still be on I've tried different hdmi cables also I've tried different tv's. I'm just wondering what the problem is and how I can fix it?