Power off struggles

[Kupfury]

My rig:

I7 5820k

H100i cooler

Asus x99 deluxe mobo

2 Asus 780s in sli

16 gb corsair vengeance ddr4 2133 4x4gb

Corsair 850i psu

2tb wd green drive

128gb Kingston ssd

Hey guys I just built myself a new machine and the only problems that I'm running into are that about 80% of the time when I turn the pc on, the monitor will still say no signal. I'm using hdmi to hook it up and everything is plugged in correctly including the video cards. I'm not sure what the problem is. The other problem I have is that my pc will randomly power off and then back on when doing non intensive things like browsing or even just being idle. My instinct tells me that my psu doesn't have enough watts but I've also heard the nightmare stories associated with the mobo I have. Any help would be appreciated thanks a lot

[Kupfury]

Also windows 8.1 64bit

[Bizarro252]

Your PSU is in no way underpowered for that build.  What are your cpu temps?  Random powerdowns could indicate a TDP shutdown??  Grab a trial of AIDA and list your temps and voltages.

[Equilibrium_FOOL]

Remove one GPU, or both (if that CPU has integrated graphics), and run it as usual.  If the problem continues, try a different PSU.

What series of PSU do you have; Corsair *** 850i?\

 

Have you overclocked your CPU?  If so you may have a highly unstable overclock. 

[Kupfury]

It is an hx850i. Right now it has gotten to a point where my monitor cannot get a signal from my pc when it boots up at all so I can't get on my pc to run any tests. I tried to do a auto tuning over clock through the Asus bios but it failed so I am assuming that it went back to stock speeds. I would check if I could actually see anything. By the way it is not the monitor fault I've used it on other builds before and it works fine

[evilarceus]

Can you try and use a different cable, like VGA or DVI, to hook up to your monitor? I don't exactly know why your computer is doing this.