Green light on computer case dimming/turning off?

Question

Well, the title doesnt really help I know but on my computer case theres a little green light that has a symbol that looks like a cylinder/battery on it and Ive noticed that its starting to dim and at one point while I was playing S.T.A.L.K.E.R shadow over Chernobyl the green light died down and my screen went black.

I dont know if it was the game or the computer itself. Anyways I have a dell dimension 4700 if that helps any

Also I dont think its a RAM problem because I have 1.5gigs on Windows XP

Answer 1

This light is your hard disk activity indicator.  The fact that it dimmed or turned off shouldn't have anything to do with the screen dimming.  The light should only be lit when the hard disk is actually fetching or writing data.