If the sticker on the drive says "Quantum" then it's definately the hard drive. Those hard drives always fail after a while.

Take a look at http://68kmla.org/forums/viewtopic.php?p=157874#p157874 if you're keen to risk trying to fix it. For a temporary fix (to recover your data), I've heard that opening the drive while it's spinning up and then manually unparking the heads can get it going. Remember to put the cover back straight after unparking the heads though.