Studio XPS 1640 scrambled screen and static problems

I have had a studio xps 1640 (Windows Vista)  for about four years now.  I have used it to play alot of hours of video games(on minimal settings though). Last night, while gaming, (about 2 hours in) the display suddenly turned all scrambled and crazy and froze. Here is a list of things i have tried so far but with no success:

I proceeded to power off and on the pc , but when it restarted the display was instantly scrambled once again.

I then booted in safe mode where the display seemed to have worked, but on looking closely i observed tiny flickering white lines appearing randomly all over the screen.

I went to Device Manager and disabled the video card. ( ATI Mobility HD 3670).  I rebooted the computer normally after this and the display looked the same way it did when in safe mode with the tiny flickering white lines on the screen. 

I Uninstalled and re-installed the video card driver then re- enabled the video card but the problem was still there.

I rebooted the pc once more and entered the BIOS this time. The tiny flickering lines were seen even in the BIOS menu. which is leading me to think it must be a hardware issue.

I also made sure the laptop screen itself wasnt the problem by doing the display test (powering on the computer while holding D). No abnormalities were seen there. I then plugged the pc into my television via HDMI. The same flickering lines could be ssen on the tv aswell.

Could it be that i may need a new GPU? Im curious about this since the flickering static lines were appearing even with the GPU disabled. But when i enable it the entire screen gets scrambled.

anyone's help or advice on this issue will be  greatly appreciated 

PC: DELL studio XPS 1640

Graphics Card: ATI mobilitiy Radeon HD 3670