I have a Dell XPS M1710 laptop with a Geforce 7950GTX 512MB graphics card.
I left it on over night and when I tried to turn it on in the morning the screen wouldn't come on(just black).
I rebooted and all the other things work but no screen...I connected it to an external monitor and the display was showing lots of pixels mixed up but still able to see...I can get it to go right to the windows desktop in safe mode(only on the external monitor) but when I try to start in normal mode get an error saying that there was a problem and windows will try to resolve but then the monitor screen also goes blank.
Take out the graphics card. Wrap the card in greaseproof paper, put into an oven at 150c for 3 mins each side. Take it out let it cool down and put it back. You will be amazed that it will work. I have done this twice already. I was a bit spectical when i read someone else had done it but i thought what the ***, if it works it works and if it don't well............. Try it, it is very easy to remove and refit. Good luck.