You might need to order a new fan, which would cost you $20 at the Asus e-store.
http://us.estore.asus.com/index.php?l=product_detail&p=3034To check to see if the fan is broken, just lift up the case and see if you hear noise after a few minutes of usage.
If you need a few pictures on removing the fan, I'd be glad to put some up. :cool:
G72GX__ GeForce GTX 260M__ 6GB RAM__ Intel Core 2 Dou CPU p8700 @2.52GHz