So about a week back, I was using my computer and it suddenly said shutting down. I then thought maybe it was doing an update, so I attempted to press the power button once off. However, before I could do so It restarted of its own accord, and then failed to actually boot for more than a handful of seconds over and over again. Eventually it did work and I used it for hours on end, and it repeated the shutting down issue eventually. While I had the computer working for that short stint, I tried to look at temperatures for the CPU and it showed 25 at boot, the Memtest86 I ran showed no memory issues after 4 passes, and the HP scan for hardware issues showed nothing. Totally dejected, I then tried to change my PSU to no avail, then did a little trial and error with the RAM chips, the GPU, and the Harddrive, once again...... to no avail. I attempted to get a response on Reddit and was met with utterly obvious suggestions, so I hope I can get more success here!
Thanks in advance! :D
PS, here's a little clip I made of the issue (ignore the rear repetitive noise that's my heater)