Question PC rebooting under graphical load or VR

[digger1213]

My second-hand 3 year old Windows 10 desktop PC has recently started rebooting occasionally with no dumps or errors in Event Viewer other than Kernel-Power "The system has rebooted without cleanly shutting down first". This happens occasionally in graphically intensive games such as GTA 5 on average every few hours of gameplay, but also happens every single time I connect my Oculus Rift immediately within 5 seconds of the Rift's display lighting up (not crashing until a few seconds after I activate the sensor that lights the displays). Thought it was my GPU but after swapping in a GTX 1060 the reboots still occurred after about 1 minute of VR usage. I suspect the PSU or motherboard, leaning towards PSU, but am looking for second opinions before I make any decisions to replace parts as I'm not certain.

Specs:
Mobo: GIGABYTE B360 AORUS GAMING 3 WIFI-CF
PSU: Cooler Master MWE Gold 750W Full Modular
CPU: Intel Core i5-9600K
GPU: GIGABYTE GTX 1070 WindForce 2X OC
RAM: Corsair Vengeance RGB Pro 16GB (2x8GB)
SSD (w/ OS): Samsung SSD 860 QVO 1TB
HDD: Seagate ST2000DM001 2TB

Things I've tried:

• Resetting & reinstalling Windows 10
• Updating drivers
• Stress testing (CPU and GPU never passed 80c in Prime95 or FurMark, notably did not reboot even after 1 hour straight stress testing)
• Swapping GPU's (GTX 1060, PC still rebooted in VR though it managed ~1 minute before crashing)
• Checking cable connections
• Plugging PC to different wall outlet

Any help, ideas or insights to this issue would be greatly appreciated!

 

[Lutfij]

Happy New Year!

PSU: Cooler Master MWE Gold 750W Full Modular
How old is the PSU in your build?

Mobo: GIGABYTE B360 AORUS GAMING 3 WIFI-CF
CPU: Intel Core i5-9600K
You would've been better served if you went with a Z series chipset as you have an unlocked processor. How are you cooling that processor? Make and model of your case? BIOS version for your motherboard at this moment of time?

Resetting & reinstalling Windows 10
Where did you source the installer for your OS?

 

[digger1213]

Happy New Year to you too!

How old is the PSU in your build?
I bought the PC second hand sometime early 2020, it's got the same PSU as then. The seller claimed it to be built new about two months prior to the sale and mostly unused. It did appear to be new as it was very clean and all components were very clean and undamaged though I can't verify for sure. I'd guarantee the PSU to be less than 4 years old.

You would've been better served if you went with a Z series chipset as you have an unlocked processor.
Most parts are as they were when I bought it, I did not choose the motherboard - definitely would have chosen something else myself, but it's what I got and didn't find it enough of an issue to change it as the CPU was already fast enough for me.

How are you cooling that processor?
It's air cooled by a Cooler Master MasterAir MA620P, the temperatures reached a maximum of 72c running Prime95 so I think it's sufficient.

Make and model of your case?
The case is a Phanteks Eclipse P300.

BIOS version for your motherboard at this moment of time?
BIOS version is F12, which is out of date, but I'm a bit scared to update given the PC's random reboots.

Where did you source the installer for your OS?
The Windows copy came from the seller with the PC and is genuine. When reinstalling, I used the Windows reset function set to remove everything and cloud reinstall Windows.

Thanks for your help!