Monitor going black and coming back on after 2-3 seconds.

I'll go ahead and make this first post long enough so that I make sure to cover as many details as I can about my computer. Today my monitor started going black/blank in the middle of tasks and turning itself back on after 2-3 seconds. The power button never changed like when it goes to hibernation/sleep mode. The sound for the game or application never skipped a beat and in fact the game continued to play as if the video had not gone blank. At first I thought it was the monitor failing, so I decided to connect my xbox 360 into the same input and played a game with equal "stress" for the monitor and it never went blank/black. It wasn't until plugging it back into the computer that it decided to randomly continue its menacing spree. I made sure that the dvi cable was plugged in correctly and that all power cords were snug. Next I unplugged my graphics card from the computer and plugged the monitor into the onboard graphics dvi output and the screen has green pixels on different shaded areas. This happened on the desktop, the POST screen and did not stop after a full install of the latest drivers. I also tried feeling the heatsink over my northbridge and and in my opinion it doesn't feel overheated but barely heated at all.

These are the specs for my PC:

MB:
ECS 890GXM-A

RAM:
Corsair CMX4Gx3M1A1333C9 DDR3 4 Gig
GSkill PC3-10666CL9-4GBRL DDR3 4 Gig (x2 Sticks)


Graphics Card:
EVGA Nvidia GTS 450

CPU:
AMD Athlon II X4 640

PSU:
LSP 650 Watt

The only thing overclocked is the graphics card. It was done with the EVGA Precision software. I haven't let the cards temperature ever reach past 70 C in it's entire time of use. Normally it would reach around 50-60 C under load of Skyrim with high resolution textures.

I appreciate any help you guys could give me.

I dont see why it matters because I already ruled out the the monitor is not the hardware at fault.
AOC 2436v

I thought this might be the case. I decided to scale down a bit on my overclocking. I believe that it's fixed my problem after I reseated my gpu's heatsink and made sure it was snug in the pci express slot.
If it fails again I'll make sure to say something. I appreciate the second opinion very much.