I've been having problems with my computer sleeping when the computer closes. Basically i've narrowed it down to the hall effect sensor but no one has that part for my computer! ifixit and powerbook medic only have it for the 12". and it's not like the 15" is just out of stock, it doesn't seem to exist. So is the thing that senses that the laptop is closed and puts the mac to sleep something else on the powerbook? I've searched for reed switches and hall effect sensors. thanks!