Question black screen, mouse and keyboard turns off.

[Lappi123]

So i have built a pc, and since i installed windows 10, my pc began doing this:

Sometimes it randomly goes black screen, and my mouse and keyboard turns off. the pc fans and everything is still running though.
This is mostly happens upon the first boot of the day. Anyone know what could be the cause of this.
This also happens sometimes when i overlock the cpu and test it in cinebench.

The tempatures in the pc are all completely fine.
System:
CPU: ryzen 5 2600
GPU: rx 580 nitro+
RAM: corsair 16gb lpx 3000mhz (X.M.P)
PSU: corsair cx550m
CPU COOLER: artic freezer 34 duo
MBO: gigabyte b450m ds3h
CASE: fractal design focus g mini
SSD: xpg sx8200 pro 512gb

things ive tried:
reinstalling all drivers in the pc.
resetting CMOS.
Updating windows.
Switching to new DP cable.
Doing sfc scan.

 

[512-Bit]

Do you have another PSU to test?

 

[Lappi123]

Do you have another PSU to test?

i only have an old 350 watt PSU to spare, and i dont think that will do it any better.
Any other suggestions?

 

[512-Bit]

This also happens sometimes when i overlock the cpu and test it in cinebench.

This symbolizes that you went too far in the overclock settings.
Try resetting your OC settings to their defaults, and let me know if you have the same boot problem.

 

[Lappi123]

This symbolizes that you went too far in the overclock settings.
Try resetting your OC settings to their defaults, and let me know if you have the same boot problem.

The problem still occurs even though all overclocks are off.
Its mostly upon boot, or about 1-5 mins after boot.