PC crashing randomly

[MONSTERvENERGY]

My PC has been crashing all day. Sometimes only a minute after start up and sometimes takes 15 to 20 minutes. When it crashes it turn off immediately with an audible click, then will sometimes restart right away and sometimes takes a couple of minutes. I've checked the event viewer and the only thing that comes up is that "The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly."

Current system build:

CPU: i5 6600k

MOTHERBOARD: Asus Z170-P LGA 1151

CPU COOLER: Hyper 212 Evo

RAM: Avexxir Core series DDR4 2400

GPU: EVGA 1070 SC

HARD DRIVES: Samsung 850 Evo 250GB (with OS installed) and WD Blue 1TB

PSU: EVGA Supernova 650 watt G2

 

Current OS is Windows 10 home. I've checked temps both CPU and GPU idle around mid to low 40s and under load will hit low 60s. No overclocks aside from EVGA's factory overclock. I have noticed that sometimes when I boot up my WD HDD will not show up as being installed. I'm suspecting it's either the mobo or psu but I'm not sure which and I'd like some other opinions before buying. Another problem I've had when I built the computer I could never get a overclock on the 6600k, no matter what clock and voltage I set it to, even at just 4ghz. At first I just figured I got the shit end of the silicon lottery but after further research I figure I would have to be the unluckiest person in the world if I couldn't even get a overclock at all, but at that point it was too late to RMA and everything was working without overclocking so I just let it go. Could this be the motherboard being defective and now causing the system crash? Or is my psu just dying and not keeping steady voltage to PC? Or am I an idiot and could it be something completely different all together? 

 

[Billy_Mays]

How old is the PSU?

[MONSTERvENERGY]

Everything was bought at the same time around 8 months ago.

[Eliehlers]

try plugging the pc into a different outlet  the same thing was happening to me about an mouth ago and when i did it it hasn't crashed since 

[MONSTERvENERGY]

No luck, still crashes