The April 2014 update of Apple's 13" MacBook Air features refreshed dual-core i5 and i7 processors, plus slightly increased battery performance.

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Where is the Reed Switch/Sleep Switch located?

I have a MacBook Air with a somewhat common problem of the screen going black when you touch the display. It is not (yet?) an acknowledged problem by Apple. Give that the problem is tied to touching/moving the display, it makes me think that it must be caused by one of two things:

pinched/worn out cables in the display module hinge

or

a faulty reed switch that is triggering sleep just by being touched

The cables will be replaced if I replace the display. But will the reed switch? If it's built into the display, yes. If it's built into the top-case (keyboard/palmrest), no. So, does anyone know where it's located. I only want to do this if I can have a very high probability of it fixing the problem no matter what the problem is.

Answered! View the answer I have this problem too

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The sleep sensor is a field effect transistor located in the upper case not the lid. The lid holds the rare earth magnet which is what sets it off. You can take a magnet and pass it across the edge of the keyboard to fire it off. Here's the display frame from a 13" MacBook Pro where you can see the magnet (outlined in Green)

Block Image

Different series had the magnet located on different sides and even the front edge if I remember correctly in the case of the MacBook Air's.

Without knowing more, I'm not sure you can blame the cable either. I would look at resetting the NVRAM & SMC logic as well as check the systems batteries health.

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The sleep sensor on these models are located on the DC in board; which triggers display sleep when the magnet inside the screen touches this area. If it is fading to black, the sleep sensor is being triggered; if it is instantly cutting to black, it is a screen/screen cable related issue.

The insulation on the LCD cable is most likely worn, which could be shorting the backlight voltage to the ground of the hinge when it is moved.

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John M will be eternally grateful.
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