PC Keeps hard locking, can't pin-point the issue

[Chicken-Select]

Hey everyone! A buddy of mine is having some PC issues as of late. He has a custom built PC and its *seemingly* randomly keeps hard locking after about 10 minutes of use. It will "hard lock" and won't return to normal until forcefully being restarted. We've done many a trouble shooting tips such a dusting the pc, making sure all fans are spinning and temps are normal, reinstalling drivers and even windows as a whole, checking SSD and HDD for bad sectors and errors, and memtest86 for RAM. Everything comes back normal. I'm guessing its either RAM or PSU, maybe MOBO if he's really unlucky. I'd just like some help pin-point some possible issues and any further trouble shooting tips anyone has would be greatly appreciated. This PC is a couple years old now but has some top shelf good components for when it was built. Here are his full specs listed below:

Processor - i7 4790K
Ram - HyperX 16GB DDR3 (2x8GB)
Storage - Samsung 840 EVO 750GB SSD
GPU - Gigabyte Geforce GTX 970
Motherboard - Asus Maximus VI Hero
Cooling - Corsair H60 Liquid CPU Cooler
PSU - Seasonic 860w 80 Plus Platinum
Case - Rosewill THOR V2 Gaming ATX Full Tower
Keyboard - Razer Blackwidow Ultimate
Mouse - Razer Deathadder Chroma
Headset - Razer Kraken 7.1 Chroma
Monitor - ASUS VG248QE Black 24" 144hz x2
Web Cam - Logitech C920

Thanks!

 

[scout_03]

strip it to minimal parts and use hwindo on sensor page to look at hte temp fans speed and voltages of the system .

 

[Chicken-Select]

strip it to minimal parts and use hwindo on sensor page to look at hte temp fans speed and voltages of the system .

He can't even seem to get the program to launch and run its tests without freezing now

 

[scout_03]

could you unplug the ssd and use a hdd with a os to see what it will do .

 

[Bfunk20_20]

could you unplug the ssd and use a hdd with a os to see what it will do .

I don't have an extra hdd but I suppose I could go grab one. Once I have one you want me to put windows 10 on it? Thinking maybe the ssd could be shot? (Btw yes I'm the owner of the subject PC above lol)

 

[scout_03]

you could use any os for the test .