Broken computer graphics, please help!

[sneil]

My computer crashed while playing Mass Effect (trying to finish it before the sequel comes out!) - it locked up, so I had to restart it by holding down the power button. When it restarted, the boot screen was all glitchy with strange horizontal lines. The same problem was on the windows start up page, and instead of going to desktop I got a blank black screen.

I restarted, ran system restore, and that is also glitchy, with weird jagged horizontal lines across the screen. The glitches move as I move the mouse around.

Tried a different monitor, no good, same problem. Took the PC apart, cleaned it out (and the graphics card didn't feel hot, particularly), checked all the connections, disconnected anything non-essential, same problem.

The computer will start in safe mode, but it's got the same wavy horizontal lines all across it. It has been working absolutely fine for twelve months, so haven't recently changed any hardware.

Is it the GPU that's malfunctioning? If it is, how come it will start in safe mode but looks weird, and is there any diagnostic tools or software fixes?

Specs:

CPU - Intel core 2 duo E6400 2.13 GHz
Mobo - ASUStek Basswood 1.05 P5BW-LA
Mem - 4x 2Gb PNY DDR2 PC2-6400
GPU - Nvidia 8600 GTS
PSU - OCZ StealthXstream 600W
HD - WD Caviar Green 1 TB

 

[mfarrukh]

Have you updated the video drivers

Try to connect monitor cable to the motherboard's integrated GPU

 

[wa1]

What about the card's temps?
Check it to make sure whether it's an overheating or not...
Also if u has another computer, u can try your card there, if the problem still exist then maybe your card is defective...

 

[sneil]

I've tried updating the drivers, they were up to date (195.62 WHQL). I tried uninstalling the graphics driver (through devices), and for some reason the computer then booted to deskptop, obviously in 640x480 (as no graphics drivers installed), but the glitches are still there, covering half the screen.

The motherboard doesn't have integrated graphics, it's external only (http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&dlc=en&cc=us&docname=c00748726)

 

[sneil]

CPUID isn't reading the card. I don't have another computer, but may have an old old card lying around I can try. I'll do that, will let you know in 15 mins or so!

 

[sneil]

OK, I swapped it out for my old 7500 LE, and it's now working. I shall start hassling my gf to give me my birthday present (a radeon 5850!) early. Fortuitous or what.

Here was the problem, btw:

http://i824.photobucket.com/albums/zz164/rneilg/c198c98da9a04b16b60974285daea560.jpg
http://i824.photobucket.com/albums/zz164/rneilg/f4d41488ef0e4d20a1eaa51b65a3ff56.jpg

 

[wa1]

Then return it to get your money back or replacement...
Maybe u got a defective card.

 

[sneil]

Too old to return but I have a replacement on its way!

How come when I give a thumbs up to someone's helpful answer (mfarrukh and wa1 in this case), twenty minutes later the thumbs up have disappeared and the score is back to 0 for both answers?