PC crashing unknown reason

Jan 1, 2019
My pc keeps crashing and i have no idea why

My specs:

Intel i7-6700k
GTX 1070
Gigabyte GA-Z270XP-SLI motherboard
12gb crucial ddr4 ram
1tb seagate hard drive
750w power supply

So for the past 6 months or so whenever i play either rainbow 6 siege, farcry primal or PUBG at a random point my PC will just black screen and then restart however this does not happen in CSGO. At first we thought it was a problem with the GPU overheating but the last time a crash happened the temperature of my GPU was only at 65 degrees Celsius. I really have no idea what is causing the problem and any help would be appreciated.
I would also look at the cpu temp....not just the gpu temp.

I would also look at the PSU voltages to make sure they were in spec.

You can do both with HWInfo.
You can do the temps with Afterburner but it has real time graphs.