Lucy's dashboard

I have a HP Pavilion tx 1000 laptop. Yesterday I was using it normally and all of a sudden the screen went black. When I turned it back on, a small warning icon (yellow triangle with an exclamation point in it) appeared at the bottom left of the screen in the toolbar. It has done this once before. Is the computer just overheating? I am worried because this computer is replacing another HP laptop I had before this where one day, the screen suddenly went black and the computer wouldn't turn on again at all.