Monitor(?) Problem

Hi, Today my screen decided to go weird. I was playing Saints Row The Third earlier - flawlessley. I then went on GTA San Andreas and then it just froze, I couldn't alt tab, I managed to end the process. That's where it begun the screen went black, I couldn't do anything but I could hear background sound. Thinking this was a one off I restarted the computer and that's when it fully ocurred - The computer loaded fine up to the 'Welcome' bit (win7) These horizontal lines were flickering but they didn't go across the whole screen. I got onto my desktop and there was more. I tried to start firefox but it just made the screen black and I had to restart. I've tried restarting a few times, leaving it off for a while, made sure the gpu was inserted correctly and made sure the cables from gpu to monitor were in correctly.

Specs:

CPU: AMD Phenom 955 X4 Black Ed

GPU: XFX DD Radeon 7950

Monitor: A 4 Year old samsung LCD

PSU: 620W cooler master

OS: W7 64

RAM: 4.00GB

I'll try to provide a picture but it's proving to be a struggle.