PC resets during games - How to trouble shoot?

[Tronnic]

Hello guys, I wanted to game a little today but my PC keeps crashing. It acts like I press the reset switch, all fans and stuff turn off for a brief moment and the PC reboots on its own (I have a setting to boot the PC after power is connected). 

 

Here's a Video of my problem, the Crash happens at 2:24:

The monitor on the right is another computer. 

 

Specs:

CPU: Intel Core i7 7700k 

CPU Cooling: Corsair H100i v2 Watercooler

RAM: 32GB G.Skill Trident Z 3200MHz 

GPU: Asus Geforce GTX 1080 ti Strix Gaming

MB: Asus ROG Strix Z270F Gaming

PSU: 650W EVGA SuperNova Platinum

M.2: Samsung 960 Evo 250GB M.2 SSD

SSD: 512GB Crucial MX, 120GB Crucial MX HDD: WD Black 4TB

 

What I tried and found out so far:

Running CPU&GPU benchmark (100% load): Crash after 5 minutes

Running CPU Only benchmark: No Crash

Running GPU Only benchmark: Crash after 5-10 Minutes

Checking temperatures, all is fine. 

Disabling all overclocks and XMP: Didn't help, same issue. 

 

I think it could be PSU or GPU. 

 

When I run DayZ at the very lowest settings and reduce my refresh rate from 120 to 50 (very low GPU load & power usage) my PC doesn't crash and works. 

 

It could be related to the PSU since the crash only happens when a high amount of energy is drawn. 

 

I get no errors or nothing, Windows Logs only show one critical error. That I didn't properly shut down the PC. 

 

No hardware changes were made recently. Only thing I did a few days ago was an larger Windows Update.

 

All drivers are up to date. The PC is about 3 years old. 

 

Any help or hint would be very appreciated. Thank you very much. I hope someone has a clue. I'm out of ideas.

[Tronnic]

I just noticed that the sound of my monitor is gone. It's connected trough DP. I didn't notice it sooner because I usually use Headphones. 

 

It shows up as "Disconnected" in the Sound Settings.

 

Also, something I noticed today. My left monitor flickered for a very brief moment (less then a few ms), showing horizontal lines. Before I could fully realize it they were gone. 

 

[Tronnic]

After a completely fresh install of windows everything seems to be working. I guess the Windows Update broke something. I still don't get why this caused a "reset" of my system without any errors or anything.

[Tronnic]

My problem is back. The only thing that has changed today is a new mouse and keyboard. Anyone any ideas?

 

Edit: Something to note: I have been gaming the past 2 weeks every day. So the system was under heavy use. Did not encounter a single problem. Just what could it be.

 

Edit2: I also just did an 2hr Memtest 86+ without any errors. 

 

Edit3: The crashes happen after a very short amount of time ingame. 2-5 Minutes. I just put my GPU Fan on 100% and its running since 30 minutes.. 

 

Edit4: Setting my temperature target to 75°C seems to fix my issue. Setting it back up to 85°C brings the crashes back. 

Edit5: Never mind, just crashed again after 1 hour.  Here are the temperature readings right at the moment of crash:

Edited September 14, 2019 by Tronnic

[Tronnic]

What component should I replace first? 

[Tronnic]

Small update, I purchased a new power supply and the system is up and running without issues. Damn, I really didn't expect that a 650W EVGA Platinum PSU with 10 years warranty would fail. Glad I tried that first.