Laptop video failure

Question

I have a Dell Precision M60 laptop. The other day the screen just went blank and the computer crashed. I was able to reboot after a minute or so into setup but the screen started showing grey, blank, vertical lines, then black and white dots and finally nothing at all at which time the computer appeared to have copletely crashed. The screen is fine for it has occasionally worked for a brief period before the line appear. What part could be causing the problem? Any ideas?