New pc randomly stuttering, chashing and restarting

[Arooo]

I built my first pc a bit longer than a week ago and while everything went went well and it booted perfectly, as i started to using it a lot of seemly random problems. First when im playing any game once every 1 or 2 hours my fps drops to below 10 for a few seconds before returning back to normal like nothing happened. Second both during game, just using chrome or using file explorer the pc completely freezes randomly, when in game the sound that last played repeats over and over until a few seconds later everything turns back to normal except when in a online game where it disconnects. Thirdly from time to time the pc just restarts, no blue screen or any error message and again comes back like nothing happened. Lastly, this only happened a couple of times while the others happen a lot, the lights on the gpu turn off, and the only way to get it working again is turning the psu off and on.
I have tried runing memtest and seatools to check the ram and my ssd/hdd no problems came up and iv tried runing 3dmark timespy the pc didn't crash and the temps never passed 50 on the cpu and 60 on the gpu so the crashes seem completely random. I would apreciate any help because i dont know how to proceed right now.
PC specs:
AMD 7 1800x
ASUS Prime x470-Pro
GeForce GTX 1070 G1 Gaming 8G
Corsair vengance LPX 16GB (2 x 8) DDR4-3000
Corsair VS550
Windows 10 Home 64bit

 

[BigFeet]

That's usually a sign of a bad piece of hardware. You've gone through most of the troubleshooting test. I'd try swapping the PSU out first of all and try to eliminate that as an issue. I'm suspecting that may be the problem. Beyond that I'd start looking at the motherboard.

 

[Arooo]

ok il try to get a replacement on the psu and check if that was the problem if not il try the motherboard next. hopefully eventually it will work out, thank u.

 

[BigFeet]

I hope you can get it solved. I know what a pain troubleshooting hardware is. You can try a clean install of windows with the bare minimum installed and see if it's still an issue. But my gut feeling is it's hardware.