This is my build.

http://pcpartpicker.com/p/CAaG

Anyways, today, when I turned off my PC I realized I had to check something, so I turned it on. The thing was, it didn't work, the PC was running, the fans were running, and the monitor was running, but nothing showed on the display. I know what I had to do, I had to reconnect the cables from the PSU to the motherboard and reconnect the GPU. I had to wait a couple hours or so before I could do this because I had to go to my Krav class. My Dad called my cousin in law because he's good with computers and he said that reconnecting the cables and GPU works half the time and that he said I should reconnect the GPU instead of all the cables. If that didn't work, it was a problem with my GPU and that my GPU might not be compatible with my operating system Windows 8 (64 bit) because its fairly new.

Which is weird because I downloaded the drivers for it from AMD's website (the driver disk for the GPU was too old so it didn't have an option for Windows 8 and Sapphire's website download didn't work so I went with AMD's website).

Anyways, I had this problem when I finished my build a couple weeks back but that was rectified because the original power supply cable was too loose and because the initial OS install was problematic so I had to do a clean install, then a week after that I opened the PC up to see if every thing was running and it was, so I closed it up and turned it back on except it didn't display everything even though everything was working. So I reconnected the cables, that didn't work, then I reconnected the cables and GPU, that worked.

And now I turn off my computer today and turned it back on quickly and nothing would display on the monitor again. Then I waited a couple hours and it works now which is weird.

So I did a normal day to day routine. I turned on my PC, pvssyd with some Steam friends, did some internet browsing on Google Chrome, play Planetside 2 for a couple hours, download a Skyrim mod from Nexus, open up Skyrim to see if it was compatible (it was compatible, the game runs smoothly on Ultra settings with mods), then turn it off because I had to go somewhere. Then I realized I had to check something, so I turned on my computer quickly and nothing displayed, I tried a few more times before I had to go do something else. Then after a couple hours it works fine.

Anyways, Planetside 2 was using 64% of my RAM if that's relevant (which is normal, its a resource demanding game, moreso than Skyrim), and I downloaded the http://skyrim.nexusmods.com/mods/31982/ with the Nexus Mod Manager.

So what's going on? Why did my PC do this? I'm thinking it will be a recurring problem if this happened again a third time.

I will clarify if you guys need more details.