Computer Randomly Restarting

[Gunni]

Hello Everyone,

So at the moment my PC tends to be restarting randomly. I'll be in the middle of something and it will just turn off, then turn back on. I have no idea why it's happening. A couple of times I have completely shut it down and when I turn it back on it tries to boot up but then stops. So all the fans/lights of my PC will go on for a second, then they will all turn off and stop. It does this over and over until I unplug it from the wall, or until it manages to boot up.

My computer specs are as follows:

Intel i5 3570K
8GB G.Skill RAM
GTX 650 Ti OC
SanDisk Extreme 120GB SSD
1TB Seagate HDD
Gigabyte GA-Z77X-D3H
Thermaltake Starcraft Case
BenQ GL2440 24" LED Monitor
Windows 7 Ultimate 64-bit

I can provide extra information if needed. Please help!

Thanks,
Gun

 

[Joe C]

What brand name and rated wattage is the power supply?

 

[Gunni]

It's a GS600, 600W PSU.

This morning I can't manage to turn it on! All the fans go on for about half a second, then they all turn off. Then it repeats; they all go on, there's a little noise, then all the fans stop. It's like it's trying to restart but there's something stopping it.