[SOLVED] Computer Randomly Crashing

[Shuuen]

Hello I built a new computer recently (early November 2018)
Specs are:
CPU: I-5 9600k @ 3.70GHz
CPU Cooler: EVGA CLC 280
Mobo: ASUS ROG Strix Z370-E gaming
Mem: G.Skill Trident Z 3200 Ddr4 16.0GB Dual-Channel
Hd: 931GB Samsung SSD 970 EVO 1TB
5589GB Western Digital WDC WD6001FZWX-00A2VA0
GPU: ROG Strix RTX 2080 OC edition
PSU: EVGA Supernova 650 G3 gold (bought the 750 to test)
OS: Windows 10 Home edition

The problem is relatively recent. Not more than a month ago, it would shut down randomly, after I stopped playing a game. I would turn it back on and it would work just fine, plus it didn't happen often. It was always after a game but more recently it shut down while gaming (2 days ago) and after trying to turn it back on again, the CPU cooler makes its normal noise but the fans do not turn on (case and CPU cooler) and it would not boot, although the monitor would react but only be a black screen. About an hour to 2 hours later it turned back on no problem. I looked online and found similar problems and seemed like all the answers were that the PSU was bad, although it seemed mine was fine, so I ordered the 750 G3 and got it today. It had been running fine the last two days, but now roughly 2 hours after putting in the new PSU, it shut off and the fans aren't spinning again. Also while it was working, I did a CPU stress test and it runs at 40c during low load, but never got above 65c at Max. GPU doesn't seem to have any problem either.
Update: computer working again (for now) I think I unplugged the Disk Drive from the PSU after it wouldnt start, and just did that now and is currently working, although unsure if that is related or if it is random. I did boot it multiple times in the last two days, and replugged in the Disk Drive with the new PSU. I have also switched the Power Cable and the outlet.

 

[Ralston18]

As I understand your post the problems seem to be related to heating up, shutting down, cooling off, and starting again.

Look in Reliability History/Manager for error codes and warnings corresponding to the shutdown times. Just as a matter of elimination perhaps. But you may discover some background app launching while gaming and then the system gets hot. Something expands, looses connectivity, and forces a shutdown.

Open the case and doublecheck that all cables, cards, RAM, jumpers are fully and firmly seated. Heating and cooling can cause minute movements that eventually lead to components creeping loose.

Look for debris or cables that may be interferring with cooling air flows.