My main pc's hard drive is predictably going to die in a short time and I need to replace the hard drive. The new hard drive when I tried to fit in in my case was banged slightly to the metal parts of the case, not other parts of the pc. The real question is, can a hard drive get damaged when banged even if it is off?
I wouldn't worry to much about a slight "bang" on the case. They are designed to absorb a certain amount of shock until there is a potential of damage. I've seen users drop their hard drive off the desk or while carrying it without harm.