Just got an old HP, how can I find out what processor fan it needs?

[etalns]

I just got an HP Pavillion A406X from a friend, and it doesn't have a processor fan on it.

I took it into a computer shop and they said they don't have one for sale.

It has an AMD Athlon 3000+ iirc (non dual core).

What's the best way to figure out what fan I need size wise? Or is there any way I can just buy a heatsink and fan that should work with it?

 

[myocardia]

You need an Athlon XP fan, according to HP. Luckily for you, a few are still available: link.

 

[Killrose]

You need a socket A or Socket 462 type H/S fan unit. The Masscool was the standard unit and if you look in myocardia's link it is about $8.00