Random Shutdown?

[Arcapse]

My computer randomly turns off, I was in the middle of playing a game, then all of a sudden my monitor displayed 'No Connection' (this happens when there isn't something trying to use it as a display).

i5-4670k

MSI Z87M Gaming

Asus DirectCU II GTX 760

Corsair Vengeance 8GB

Corsair CX600M

WD Caviar Black 1TB

[Volbet]

Does it just turn off and stay off or does it restart immidiatly after shutting down?

 

It might be a problem with the PSU or the RAM

And if you have any overclocks on the GPU, CPU or RAM you should scale them back to their default settings 

[Arcapse]

Does it just turn off and stay off or does it restart immidiatly after shutting down?

 

It might be a problem with the PSU or the RAM

And if you have any overclocks on the GPU, CPU or RAM you should scale them back to their default settings 

It stays off and I've never overclocked before on this system.

[Volbet]

It stays off and I've never overclocked before on this system.

OK then.

 

Make sure all the internal power connectors are plugged in securely and test the RAM by running Memtest86. This will give us a place to start.

[Arcapse]

OK then.

 

Make sure all the internal power connectors are plugged in securely and test the RAM by running Memtest86. This will give us a place to start.

I used mdsched.exe instead because I don't have an optical drive nor a USB Stick. It says there are no problems. Now, how would I check the power supply?

[hiyayhi]

You can buy a PSU tester on ebay for a fairly good price but you want to make sure you get one that actually works... also I HIGHLY suggest getting a usb to run memtest86 on, also use a CPU burn in test to test the cpu, unlikely but possible, look at the temps of everything like CPU and GPU to make sure everything is at acceptable levels when idling and in the situation it crashes in. Next you want to try and test the HDD, I had a HDD fail on me in this way, a good program is seagates hdd tester but I am not sure of the actual name, I could probably dig it up for you.

[Volbet]

I used mdsched.exe instead because I don't have an optical drive nor a USB Stick. It says there are no problems. Now, how would I check the power supply?

Try a different PSU in the system if possible or try the PSU in another system.

 

Also do what @hiyayhi said. 

[hiyayhi]

Look up Seatools, a very good program for testing HDDs.

[Arcapse]

Look up Seatools, a very good program for testing HDDs.

 

Try a different PSU in the system if possible or try the PSU in another system.

 

Also do what @hiyayhi said. 

In SeaTools, it doesn't detect any Hard Drives, and now Windows 8 notifies me it is shutting down.

[hiyayhi]

Strange, this is with the computer the problems yes?

 

To be honest I have never encountered that problem.

 

Does your Bios have S.M.A.R.T status check? You could try a different HDD tester like HDtune, also check in the bios that the drive is set to IDE mode not ACHI.

 

Other than that you could try booting off of a different hard drive and see if that helps. Make sure you do not have the first drive installed at the time though in case it is a malware or other malicious software problem.