So we've all read people's stories about dropping macbooks and the consequences, hrrible or otherwise. None of those stories have covered what happened to me, though, so I'm looking for help here. I dropped my macbook from a height of around six feet. Impressive, especially since there's no physical damage- at least externally. However, whenever I turn it on or wake it up, it makes a sort of choking mechanical sound, like the normal one only louder and more stuttering. It's also the exact same noise every time. This hasn't affected anything except the disc drive, which I can no longer get discs into without them getting hideously scratched. Any ideas on what might have happened/what I can do about it/how mch repairs would be?