The G-force sensor only works when the power is on, as far as I'm aware.. The drive wouldn't have time to spin up and park in the time it takes to hit the ground. A drop usually won't affect the drive too badly, but as dntalk pointed out, the IDE cables can come loose, and maybe (less likely) the power to the drive.. If you're familiar with laptops, you could attempt to open it, but don't even think about it if you haven't opened one before. They typically have little hidden catches and you'll need to know where to lever the case off. They're also quite delicate inside.