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Keyboard & Trackpad not found on 13" A1278 2012 MacBook Pro

edited February 2015 in MacBook Pro
Hi there,

The keyboard and trackpad are not recognised at all on my 13" A1278 2012 MacBook Pro, which is odd as the power button still works without issue. Everything else functions normally, except that the keyboard and trackpad are completely unrecognised (no mouse movement at all, no keys work).

I have tried a PRAM reset using a USB keyboard, running Apple Diagnostics (which found no issues whatsoever), I've cleaned the logic board thoroughly with isopropyl and a toothbrush (the MacBook had suffered liquid damage, got it second hand), and I have tried replacing the trackpad and cable (which remained completely unrecognised, it is now in another MacBook and works 100%).

I have also tried installing a fresh copy of Yosemite to no avail.

Is there a component which controls the input from the trackpad and keyboard? Both the keyboard and trackpad connectors on the motherboard appear completely fine, and the power button works without issue.

Any advice would be greatly appreciated,
Thank you!

Answers

  • edited March 2015
    Thanks for the post!

    The odd thing here is that BOTH the trackpad and the keyboard are not working. The trackpad has its own connection to the board, and the power button and keyboard share the ribbon cable connector, so if two components connected by two different cables are not working, that would suggest the board may be suspect.

    Since the power button works, you may have fried your keyboard, and replacing the power button/keyboard (they are connected to each other and effectively one part) might restore the keyboard.

    But again, the trackpad is independently connected to the board, and so it would seem to be a separate issue, and likely is board damage. You have tried a known-good trackpad, so there's little doubt the problem is on the side of the board. I would boot from an external hard drive to rule out a software problem, but you've basically already done that by re-installing Yosemite. I would also try disconnecting the ribbon cable and jumping the board via the power-on pads, and seeing if the trackpad works when it comes up...if it's true that both share a "common component" on the board as you suggest, this test might be useful in determining whether a faulty keyboard is somehow inhibiting the trackpad from working. A fried keyboard, for example, will often keep the power button from working, and will also often keep the board from being jumped if the ribbon cable is still connected, so it's a worthwhile test, and pretty much the only thing you CAN do, short of getting into board repair.

    Yeah, unfortunately, I think you're now faced with the realm of component-level board repair, which a black hole of knowledge I'm just not very well acquainted with. You could always check with rossmanngroup dot com -- they are a very reputable Mac board repair company, and they might offer a reasonable solution.

    Thanks, and let me know how it goes!

    John
  • Wow, thank you for the informative and quick reply John.

    I actually did try a different hard drive from another MacBook this morning and the result was the same. I didn't even think if the keyboard could be inhibiting the trackpad so you're right, that sounds like a worthwhile test.

    I have just watched this video based on your recommendation which has given me a couple things to try also:

    youtu. be/fh4hpM8JyvM

    David
  • edited March 2015
    Great! I'm glad you found Louis Rossman, because he is awesome and his videos are an incredible resource. I watch them all the time, but they are usually way over my head. :-)

    Good luck!

    John
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