[SOLVED] Black screen/Crash only in games

[Brightwing]

Yesterday I've updated my PC and ran into a problem that everytime I start any game, it works fine for about 10-30 seconds and then monitors go black, while sound still plays normal for some time and then only reset button helps. It happens only with games, everything's okay in system, not to mention that everything works fine with AIDA64 stress test going for half an hour. (not sure if it's worth mentioning)

Things I've done so far:
-Clean Windows 10 installation with all needed drivers
-Tried different video driver versions
-Сhecked temperatures
-Tested RAM using Memtest86
-Tried installing different chipset drivers (from motherboard page and from amd.com because there's newer version)
-Checked if unplugging one of monitors would change anything

Just in case, I've updated everything in my setup, except GPU and hard drives.

Specs
CPU: AMD Ryzen 5 3600
Motherboard: MSI B450 GAMING PLUS MAX
Ram: Kingston HyperX Fury Schwarz 16GB DDR4 Kit RAM | HX432C18FB2K2/16
SSD/HDD: Samsung SSD 850 EVO 120GB / WDC WD10EZEX 1GB
GPU: ASUS STRIX GeForce GTX970-DC2OC-4GD5
PSU: Seasonic Focus Plus Modular 80+ Gold 750 Watt
OS: Windows 10 1903 with all updates

 

[RaidHobbit]

Have you made sure in device manager than your onboard graphics are turned off? Your display may be switching to that.

 

[Brightwing]

Have you made sure in device manager than your onboard graphics are turned off? Your display may be switching to that.

As far as I know this CPU doesn't have integrated graphics, so there's only GTX 970

 

[Brightwing]

I guess it's something with motherboard, because I've tried other PCI-E X16 slot and everything works a little better, I don't crash after 30 seconds but 5-10 minutes.

 

[RaidHobbit]

I guess it's something with motherboard, because I've tried other PCI-E X16 slot and everything works a little better, I don't crash after 30 seconds but 5-10 minutes.

Sounds like overheating or driver becoming unstable.

Maybe time to clean all dust from PC?

 

[Brightwing]

Sounds like overheating or driver becoming unstable.

Maybe time to clean all dust from PC?

Well, I assembled it only 2 days ago, so I don't think dust should be a problem. Not sure about a driver, because it looks like GPU randomly stops giving a signal, or that's a driver crashing without recovering.

 

[Brightwing]

So I guess it has something to do with this https://www.tomshardware.com/news/seasonic-focus-plus-psu-compatibility-issues,38105.html

Because I've tried using my old PSU and problem is gone.