Help Inspiron 1564 Problems! Not sure if LCD or GPU or something else entirely!

Hello All

I thought I'd post here as I'm totally stuck, my laptop has gone off for repair today but i'm worried its going to come back with the same problem.

basically every now and again without rhyme or reason the screen changes to a multicolour snow/static effect (like white noise on old tv sets) the fan increases speed and then it shuts itself down. The amount of time before it does this seems to vary and when I feel the bottom of the laptop its not exactly hot or even warm for that matter. Tech support tried to view the windows event log the other day but before he could investigate the laptop turned itself off again...he did manage to spot more than a few critical errors though so he just ordered a pick up for repair to investigate. Anybody else experienced anything like this? What was the problem and how was it solved? ....i just want a happy working laptop :)

thanks in advance

Stacey