[SOLVED] My PC power cycles/restarts every now and then, What should I do?

[Coziest Man]

During random loads (idle-to-intensive) my PC sometimes power cycles randomly. Sometimes it also completely turns off all my peripherals (keyboard, mouse) and monitor signal and the fans go to the loudest setting. I can't power it down with the power button during this, and I have to manually shut off my power supply. At first, I thought this was my power supply but I replaced it and it is still happening to my PC. Can anyone help me with this, I am seriously worried.

PC specifications:
CPU - AMD Ryzen 7 2700x
CPU Cooler - Corsair AIO H100i PRO 240mm
Motherboard - Asus B450-f motherboard ROG Strix
RAM - 16gb (2x8) 3200mhz G.skill Ripjaws V
GPU - MSI Gaming Z Geforce RTX 2070
(OLD) PSU - EVGA BQ 650 W 80+ Bronze
(NEW) PSU - EVGA SuperNOVA G3 750 W 80+ Gold
OS - Windows 10 Home
Storage: Sandisk 240gb, Seagate Barracuda 2tb

Thank You

 

[Vic 40]

If you don't have the latest bios update to it.

Other thing,make sure the VRM's have enough airflow over them,maybe these are overheating. Look at temps anyway.

 

[rolli59]

You have eliminated the PSU. Have you tried running with individual ram sticks? Can you test your GPU in a different system? If either test does not find the problem most likely motherboard issue.

 

[Coziest Man]

If you don't have the latest bios update to it.

Other thing,make sure the VRM's have enough airflow over them,maybe these are overheating. Look at temps anyway.

I have the latest bios, for the VRM's should i try higher rpm on my case fans?

 

[Vic 40]

What case and hoow are fans configured? If more fans at the back try the real back fan as output and topfan still as input.
Looking at this should do the cooling work well,but who knows,
ASUS ROG Strix B450-F Gaming Review | VRM Temperatures | CPU & Mainboard | OC3D Review
Might just be that the motherboard isn't good as rolli59 said,but more testing might bring that to light.

What you also can try is power the gpu with two cables,not just using one cable=two connectors.