I have a black a1181 macbook pro that won't go to sleep when I close the lid. I know that the previous owner replaced the screen so I don't know if he messed something up there, however when I slowly slide a external hard drive ( a spare one not connected to the computer in any way) along the left side of the lower case next to the keys it goes to sleep (by left side I mean the one wear the power chord plugs in), so I don't know if the reed switch is bad or if it isn't high enough? Or if it's the reed switch at all? any help or guidance is greatly appreciated