Macbook Air 2008 help

Hi all,

I have a Macbook Air 2008, Model 1,1 A1237 which on startup makes 'the three beeps' noise and then fails to boot. I've been told by some Apple bods that it is most likely a hard disc problem, but i've also been told it could possibly be a problem with the thermal paste around the heatsink. Any help/advice/info would be most appreciated

J