How To Fix The Broken Latch On Your Last-Gen Macbook Pro, Which Is Why Your Lid Won’t Close (Noscope)
If the lid on your last-gen Macbook Pro won’t close, the cause is probably a stuck latch. A clever gentleman on the Apple support forum has invented an ingenious toothpick trick, which can help you fix this problem. We’re told that pushing the small metal pins inside the two rectangular holes just below the trackpad, you’ll eventually hear a liberating “click”, and for most people that should be it.
For me it didn’t work, until I pressed the metal pins while the Macbook was upside down. This leads me to believe that the cause of the broken latch is some cruft that’s stuck between the edge of the Macbook and the depressed latch mechanism, as I’ve tried to illustrate. Let me know if it works.
via noscope.com
Worked for me :)