Why does keyboard and trackpad not work
Keyboard and trackpad do not always work in low light. Ribbon and top plate have been replaced, as has left light sensor. Does the same thing with or without battery installed, and with different versions of OSX. PRAM has been reset with external keyboard, but does not stay reset. Boot machine into low light and keyboard is inoperative as is trackpad. Move it into bright light and they start to work. It will continue to work if moved back into low light but if both sensor areas are covered they stop working again until moved back into bright light. Keyboard is inoperative on boot up in either case.
Anyone have any ideas?