Computer crashes after couple hours

[DiX0Pi]

So I'm here playing LoL and my computer crashes within 4 hours of being on. I turn the PC back on instantly and get to playing, not even an hour later it crashes again. I turn it on again and I go back to playing games and crashes. I don't understand because my temps are all perfectly fine.
My Hardware:
GPU: GTX 1070 Windforce OC
CPU: i7 2600
RAM: 16GB RAM 1333 MHZ DDR3
PSU: 750W EVGA 80+ Certified PSU
MOBO: Some BCM Model

I feel like the motherboard is just getting old and is time to get a new one.

 

[Vic 40]

It only happens when the system is under stress? Gaming or editing ,stuff like that.\
How old is the psu?

 

[DiX0Pi]

It only happens when the system is under stress? Gaming or editing ,stuff like that.\
How old is the psu?

If i leave the computer sit for a while and play all of the sudden it will be fine, but after I start using constantly thats when it randomly crashes. It usually happens with just normal use without gaming or with it. The psu is about 1-2 years old, it is a 750W 80+ bronze certified EVGA semi modular PSU.

 

[Vic 40]

What do you use to check temps?

download hwinfo64,
install and open it,
check "sensors-only",
click "run".