As far as I've seen the keys are anchored with a kind of a hook from one side (the one you don't play on), and also with a piece of metal wrapped with teflon that goes into the key near the playing end.
Sorry, I don't have pictures of that.
So if the keyboard is the same, the only way it could rattle would be if someone removed the teflon that was wrapped off of the metal piece that goes into the key.