Both Command keys as well as zero digit not functioning on MacBook keyboard

Question

My left and right ⌘ Command keys are being extremely unresponsive on my MacBook Air (13-inch, Mid 2012). They might work for hours and then stop working again. The odd thing is that when they do stop working, so does the number zero (0).

Mashing the three buttons all at once (as one does when in frustration) sometimes solves the issue temporarily. I'm using the digital keyboard viewer in the case that i need to use a "0", and the " ´ " (directly to the left of Delete) key seems to constantly be orange.

Strangely this highlight disappears when pressing either of the ⌘ Command keys (using the mouse to press them on the keyboard viewer). Now, the thing that confuses me the most is the fact that when pressing both ⌘ Command keys as well as 0 (physically), then pressing the highlighted "´" key, it types out "n´-" instead of just "`", which should be expected if the other keys weren't functioning.

All of this boggles my mind. Is there some simple thing I'm missing? I refuse to get my keyboard replaced as that last oddity implies there's nothing wrong with the keyboard itself...

I've just found that a more reliable temporary fix seems to be to hold down both command keys, however pressing 0 once will undo the fix.

Answer 1

Your keyboard is failing and should be replaced.

The keyboard is made up of "layers" with one of them being a flexible plastic "circuit board" with conductive traces. The photo below shows a typical example of this (Disassembled keyboards from MacBooks aren't common so I used a PC keyboard - the technology is the same).

Update: I wrote a canonical Q/A on this topic that shows much better breakdown of the keyboard assembly and goes in depth as to what the issues could be.

The keyboard recognizes a key press when a particular circuit (or circuits for multiple key presses) is/are closed. It's a physical connection being made.

If anything gets between the contacts or if the contacts become worn, the keyboard will begin to malfunction as yours is doing now.

This will only get worse. Keyboards don't fix themselves and software fixes only go so far. Your best bet is to replace the keyboard - and there's good news and bad news...

The good news: A replacement MBA keyboard is relatively cheap; less than $20.

The bad news: Replacing the keyboard will require you (or a tech) to completely disassemble your MBA. This involves literally taking every single component out of your MBA. It's not a hard process, but rather a long and detailed process. Ifixit.com has an excellent step-by-step.

If you feel comfortable around electronics and you have done this type of thing before, I recommend that you give it a go at replacing it yourself.

If this is not something you are comfortable with, I suggest hiring a tech.

Answer 2

The key thing to understand here is that even if your keyboard has a 100 keys, there aren't 100 on/off switches with wires to your motherboard -- that would be too inefficient. Instead, characters have codes, and it is these codes which are sent through these wires, and the number of wires will be much smaller. (This is also why you can't press more than a few keys simultaneously)

Therefore it's possible that if one of these gets shorted for some reason, (spills being the most common) a particular set of keys would stop working as expected, while leaving the others unaffected. Sadly Apple doesn't repair keyboards, only replaces them. I had to give up a perfectly good Apple Keyboard for just 4 keys like you. In my case it was the left and right arrows, left command, and tilde.

EDIT: Whether or not it's a software error should be easy to check -- try the following (in order): - New user account - Different OS (Windows via Bootcamp, or just an Ubuntu Live USB)