Random system freezes/crashes without BSOD

[NIK220V]

So, i'm experiencing two types of crashes.

■ Image on the screen and sound (will loop repeatedly) freezes. Whole system freezes i think, because no actions are done in this state. I need to manually shutdown computer and start it again.
■ Computer turns off, and then turns on by itself. That's a crash too, because programs aren't closed properly.

No BSOD/Minidumps in both types of crashes.

What i have tried and done already:

• 
  ■ Replaced my old PSU with a new one, because it looked like it was a PSU fault. Well, looks like it wasn't.
  ■ Used memtest86 to test RAM. Ran it for 9 hours, 4 passes completed with 0 errors.
  ■ Ran IPDT test for CPU. Passed it with no errors. (Average CPU t. is 50 °C)
  ■ Used FurMark to test GPU. Looks fine too. (Max t. < 70 °C)

And now i have no idea about what causes crashes.
Any help would be appreciated.

Computer specs:

• 
  ■ Core i5-2500K
  ■ GTX 950
  ■ AeroCool 600W VX 600 PSU
  ■ 2x DDR3-1333 4GB and 1x DDR3-1600 4GB
  ■ Samsung 850 EVO 256GB SSD - System drive, and a bunch of HDDs .
  ■ Windows 10 Pro x64
  ■ ASRock P67 Pro Motherboard

 

[Dark Lord of Tech]

More than likely it's the very very poor Aerocool PSU.

 

[NIK220V]

More than likely it's the very very poor Aerocool PSU.

Are you sure it's that bad?
Those crashes didn't start from the beginning.
I bought GTX 950 more than half a year ago, SSD around that time too, but system was working quite stable.

It became very frequent in the last month or so.
And as i said, this PSU is new, i replaced my old one (which apparently was even worse), and i can't see any difference.

 

[Dark Lord of Tech]

Just my opinion , I wouldn't trust an Aerocool PSU.
http://www.tomshardware.com/answers/id-3211628/aerocool-600-600w-power-supply-run-290x.html

 

[NIK220V]

Just my opinion , I wouldn't trust an Aerocool PSU.
http://www.tomshardware.com/answers/id-3211628/aerocool-600-600w-power-supply-run-290x.html

Thanks.
I looked into mine PSU's comments on the store website (around 300 of them), all look mostly positive and people who asked about even better PC builds than mine are saying that it's working perfectly fine.

Any other ideas?