Question PC freezes randomly + No POST? Undiagnosed issue.

[anyone22]

My PC randomly freezes, sometimes it happens after hours of use, sometimes, not even 5 minutes past boot. Weirdly, something still seem to be working somehow, like today after freezing the PC played the sound notification for web whatsapp, but got no response from mouse/keyboard and the windows clock remained frozen. Ctrl + Alt + Del also unresponsive.

It has been happening for months, but now the freezes are getting more frequent. Also, when it started, all I had to do is press the reset button, and everything would be back, now when I do that the PC doesn't boot. Everything seems normal (pc lights and sounds), but the monitor stays in the "no signal" mode. I suppose this means No POST.

So I end up having to take it out from power and waiting for a few minutes before turning it on again.

So far I've tried:

• Windows memory diagnostic tool (normal and advanced)
• Memtest 86+ (7 passes 0 errors)
• Cleaning the memory and switching the slots
• Stress test with AIDA64 (no freezes)

- CrystalDiskInfo (all good)
- Clear CMOS (Caused me some "inaccessible boot device" trouble, that's now solved)

I'm not sure what else I can do to diagnose the issue. Every suggestion is welcome

Hardware:

CPU: i7-4790k
Motherboard: Asus Z97-A
GPU: Gigabyte GTX-970
PSU: Corsair AX760
Memory: 2x 8GB G.Skill DDR3
SO in Samsumg SSD
4 HDDs (Toshiba and WD)

 

[Koekieezz]

My PC randomly freezes, sometimes it happens after hours of use, sometimes, not even 5 minutes past boot. Weirdly, something still seem to be working somehow, like today after freezing the PC played the sound notification for web whatsapp, but got no response from mouse/keyboard and the windows clock remained frozen. Ctrl + Alt + Del also unresponsive.

It has been happening for months, but now the freezes are getting more frequent. Also, when it started, all I had to do is press the reset button, and everything would be back, now when I do that the PC doesn't boot. Everything seems normal (pc lights and sounds), but the monitor stays in the "no signal" mode. I suppose this means No POST.

So I end up having to take it out from power and waiting for a few minutes before turning it on again.

So far I've tried:

• Windows memory diagnostic tool (normal and advanced)
• Memtest 86+ (7 passes 0 errors)
• Cleaning the memory and switching the slots
• Stress test with AIDA64 (no freezes)

• CrystalDiskInfo (all good)
• Clear CMOS (Caused me some "inaccessible boot device" trouble, that's now solved)

I'm not sure what else I can do to diagnose the issue. Every suggestion is welcome

Hardware:

tried to unplug gpu and use igpu only to recreate the problem?

 

[anyone22]

Thanks @Koekieezz
Since the issue is very intermitent I may not be able to recreate the problem. I'm going to be using igpu for one or two weeks, but even if it doesn't freezes it doesnt really mean that is was the GPU. (Obviously if it does freeze, it exempts it)
Is there anything else I can do for testing a gpu? Would a stress test be helpful?

 

[Koekieezz]

Is there anything else I can do for testing a gpu? Would a stress test be helpful

testing it on another pc is the best way to go, to know if its the gpu faulty or your system faulty.