MacBook Air keyboard has dead keys temporarily on startup and waking

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Level 1

11 points

MacBook Air keyboard has dead keys temporarily on startup and waking

My MacBook Air keyboard has developed a fault where the space bar and other keys (tab, down arrow, fn, tilde and quotes) do not register on startup.

This is true even when typing in the login field on a normal startup or when entering repair mode.

If I connect a bluetooth keyboard, the keys on that work normally.

The fault usually appears when the computer starts or wakes. Sometimes, if I have been using it earlier in the same day, the fault does not appear - unfortunately the situation when I took it to the Genius Bar (I had filmed the behaviour on my phone so was able to show the assistant what was happening).

As the fault occurs with the inbuilt keyboard even when typing in the login field to enter repair mode, it appears to be unrelated to the system or any settings or other software (it's nothing to do with accessibility settings).

The Genius Bar did a firmware rebuild, but that has not resolved the problem.

Even though it is inconvenient, the dead keys will suddenly start working again and work with no further problems until the next restart or a long sleep.

When the keyboard starts working normally is not time dependent - if I use the computer with GarageBand and my midi controller the dead keys continue to be dead indefinitely.

However, if I type, the dead keys suddenly come back to life (I copy a space and use ctrl-v to be able to work until the spacebar and other keys start working).

I've experimented at the stage of typing in the login field at startup to investigate what is required to get the dead keys working normally.

Pressing the dead space bar repeatedly does nothing.

However, if I alternate pressing the space bar and a working key (deleting the text from the login field when it is full) the space bar will start working after filling the login field around 20 to 30 times.

If I press a working key without alternating the space bar, the space bar remains dead when I do try it. It requires both a working key and dead key to be pressed alternately multiple times to bring it back to normal operation.

The Genius Bar said they will send the computer off for a keyboard replacement after I have done a clean install of the system. I will try that but cannot see this is system related when the problem manifests when booting into repair mode. Hence, the decision to try the firmware rebuild.

The assistant said they had never seen this specific problem before.

So, has anyone else come across it and was a keyboard replacement the required solution?

MacBook Air 13″

Posted on Apr 26, 2023 2:46 AM

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Answer 1

HWTech

Level 9

68,384 points

Apr 28, 2023 7:35 PM in response to mikebrady

The two most likely parts which could be causing this are the Keyboard and the Logic Board. It is hard to say for sure which one is causing the problem. I've encountered odd issues with keyboard behavior....where the keys work fine at the login screen, but fail to work once logged in....plus I've seen it the other way as well. Sometimes it is the keyboard, other times it is the Logic Board. The keyboard is a good place to start though.

If you have a 2018+ model, then the best option would be to "Restore" the firmware which resets the firmware and will push a new OS onto the computer (on some Intel Macs, it may be required to reinstall macOS using Internet Recovery Mode after the "Restore"). Since it restores the firmware perhaps will do something to fix the issue (more likely an an OS issue). Unfortunately this requires access to another Mac running macOS 12.4+.

Revive or restore an Intel-based Mac using Apple Configurator - Apple Support

Revive or restore a Mac with Apple silicon using Apple Configurator - Apple Support

Make sure to test the laptop before installing any third party apps and before migrating/restoring from a backup. Apple just wants to make sure that some third party app is not causing a problem (or possibly some corrupt setting).

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Answer 2

mikebrady Author

Level 1

11 points

Nov 17, 2023 10:16 AM in response to mikebrady

Okay, here's an update on the weird history of this problem, which disappeared, came back and disappeared again.

The problem as described in my initial post first surfaced after a long flight from Brazil to the UK. I had left the computer on with the wi-fi deactivated because I wanted to work on the flight and certain software had to check my license online when first opened it, which I couldn't do on the plane without an internet connection. So, I activated the software at the airport, switched off wi-fi and closed the screen to enter the plane.

In the end, I didn't use the computer on the flight and when I reached my destination the problem had appeared. I put it down to leaving the computer on for and extended period while closed.

The problem disappeared when I returned to Brazil. I was showing family around and used the computer only infrequently and thought the extended off time had somehow cured it.

Yet, when I returned to the UK, the problem reappeared.

Several months later, I'm back in Brazil again and the problem has gone once more!

It seems it's either linked to the location or to the change in time zone. I don't see how either of those could be relevant.

I fully expect when I return to the UK next year, the problem will appear again. I suppose I can try manually changing the time then to see if it makes any difference.

I am now using the computer as much as when I was in the UK, so I would have expected if time of use was the issue, the problem would have recurred by now. It hasn't, two weeks in.

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Answer 3

mikebrady Author

Level 1

11 points

May 4, 2023 3:46 AM in response to HWTech

Thanks for confirming this is not a unique incident. We did try a firmware restore at the Genius Bar, but it did not solve the problem. I will try the clean system install before arranging to send it off to repair and will report back.

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Answer 4

mikebrady Author

Level 1

11 points

Jun 21, 2023 12:55 AM in response to mikebrady

My keyboard stop manifesting this problem about a week ago. I can now type spaces in the password field when first starting and all keys work normally. Previously, the space bar and certain keys were inoperative at this point - and even when booting into diagnosis mode.

I never did get around to doing a clean install of the system.

And I have not installed any system update that might have corrected the problem. I'm still on Ventura 13.3.1, as recorded in the diagnostic reports I ran when the fault was active.

This problem began in March and persisted until June.

It is a mystery why it has gone away now, but I hope it won't come back.

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MacBook Air keyboard has dead keys temporarily on startup and waking

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