So I've got two bad iPod HD's. I wanted to figure out what fails on them. I open up the 20GB one (THe one thats not in my iPod) and low and behold... the heads actually have come OFF the arm where it reads the platter! I'm making an attempt to superglue back into position and see if it fixes the problem. If so, this is something that a few skilled people can do to fix otherwise useless iPods!