I have just been given two of these machines, both of which have probs. I will talk about this one first and come to the second one in a later thread.
I put a 30Gig Drive in it and set the BIOS to boot from CD to install anew op system for my daughter. It starts up and then immediately powers down before it does anything more. The onboard fan also appears to be a little noisy too with a moderately loud whirring sound. Any ideas to get me started please.

Is this with AC power plugged in or is this just on battery?

Try taking the battery out for a half minute or so and then putting it back in.

I have tried this on battery only and also with the mains

Did the machine work before you set it to boot from cd?

Well I guess it had to have in order to change it to boot from cd, huh.

If possible, remove the cd drive and see if it boots.