So I've gotten a 40GB 4th Generation iPod from a friend of mine. At some point in shipping, the iPod must have been knocked about and the hard drive is now dead. I do happen to have an old 20GB iPod (same generation) that has long since been dead (bad logic board). Since both iPods are of the same generation, I should be able to take the old 20GB drive and install it in the 40GB unit, right?