High end custom built PC crashes with buzzing sound, no BSOD, when gaming

[jordan.t.olah]

My PC keeps crashing when I play graphics intensive games after about 10-15 minutes of gaming with no BSOD. I.e. the screen freezes.
PC is about 2.5 yrs old and I built it myself.
It used to only happen playing the witcher 3 after long periods, now happens playing Fallout 4, using a Wii U emulator and even happens after playing simpler games like Broforce now.
I did some research and discovered that the PSU is a common fault in this issue and have upgraded from a basic use 750w to a gaming ready 850w and still encounter the issues.
Please let me know what I can do to troubleshoot this issue. Thanks

 

[hang-the-9]

Need full system specs including the power supply brand and model.

Did you test the video card in another known good system? If not, do that and see if it does the same thing. Also test temps while running something like a game or benchmark.