GOOD GOD HELP new built Pc turns on them off after approx 10sec no display

Figured out mobo was bad got a new one and everything is working fine except one thing, when i leave my pc on for about 4 to 5 hours when i go to play any game it shuts off without rebootin, ill post a thread with more info but if anyone knows anyhting it will be greatly appreciated.

Can you please respond to my other thread where PC shuts down after prolonged use, I fixed this problem, I believe it may have to die with having my PC 2.1 surround sound system, and monitor all plugged into a fairly old power strip but I'm not certain, would this cause a PC to shit down and not reboot when running for a prolonged time or at at high use

I just finally got a working pc built. i cloned my old 1tb hdd to my sdd, pretty much no problems everything starts up faster than ever but ive noticed this now twice. when i left my pc on to clone the drive initially for about 2-4hours approx. when i went to try and play fallout 4 the whole pc shut down at the loading screen no reboot, i had to flip the psu switch to off mode and back on again before it rebooted. in the morning it worked fine everything played great. today i was downloading the new battlefront for about 5hours playing fallout 4 on and off. then i went to start rome 2 total war and while i was in the custom battle menu selecting units it shut off again excatly like last time, i did the same thing with the power switch and it turned on like normal.

The first time it shut down was on my old msi b85-g41 mobo the second time was on the new msi gaming 5.

Idk whats going on is it that the pc has been on too long, on my old pc with old mbo and hdd i could leave it on all day or play for hours and never a problem with shutting down and my cooling was garbage compared to this one.

Every component but two sticks of ram 2x4gb are no more than a month old and that ram is from last xmas. this is my 4th build since i got into pc gaming about 10 years ago, at least to my knowledge all cables are secured, everything properly mounted, cpu properly applied thermal paste.

Specs:
Raidmax vampire case
i7 4790k
nvidia 980 TI
16gb 1866mhz ram 4x4gb sticks
samsung 1tb ssd
msi gaming 5 mobo
thermaltake gold 850w psu
4x 120mm fans, 1x140mm fan, 1x200mm fan
coolermaster cpu cooler


EDIT>>>>>>> 11/20/2015

I came home from work after about 14 hours or so PC off all day.
I turned on pc it started up fast and normal. I began downloading the latter 10gb of the new battlefront.
it was on for approx 1 hour and 30min. I started up fallout 4 with origin still downloading battlefront in the background. I was able to play for about an hour when the pc shut down again, no reboot. i did the same process as before and turned switch on and then off it rebooted as normal. I restarted the battlefront download. i tried to play an older game, Napoleon total war, it again shut down in the custom battle menu.

Is this a bad PSU, an overheating CPU, bad RAM, bad GPU, a bad wall outlet, or a result of cloning to a SSD as opposed to a clean install, do i need a higher speed ram that runs at a speed higher than 1866MHZ running origin in the background???? I use MSI afterburner and all temps appear normal cpu usage is high. On my old rig with a hdd, older mobo i never had this problem.

Please anyone who knows more than me and im sure theres plenty, please help. Im about ready to take my PSU, and CPU, back to frys get an echange for something comparable or return the ssd to amazon and get a new one, or hell if its my gpu return that as well, or buy newer faster ram. I have no idea.

I work in EMS and my time is limited on these things I maybe get a day off a week and i would love to spend it playing a PC that works as well as this one but doesnt give out on me. I have never had a PC that got 40-60+ FPS on the newest games but it sucks that it shuts down.