Nowadays notebook hd in laptop, ssd hd, sound cards, video card, motherboards, car engines, all have covers. I don't know why 3.5 inch drive does not.
I had 2 hard drive that died because of mishandling. One caught on fire, the other one I think the smooth chip got shorted and then the head keep clicking.
They were all prefect in the SMART status..
As to Seagate Barracude IV 80GB, you mean like this? (I briefly searched google but could not find anything much)
Its hard to find pictures of the pcb side of the HD. I guess it has to be 'server/industrial' grade for the pcb to be protected..