I have a MacBook running 10.6 that was given to me for repair. The keyboard and track pad do not function. It work fine with USB attachments. I have done a repair of the OP system along with reset of everything I can reset. I have found if left overnight and then turning on the keyboard and track pad will work up to the point of signing in to an account before going dormant. If restarted at that point, the keyboard and track pad will not reactivate until left off over night again . ???