Weird keyboard issue - 2019 MBA

[SnowCrocodile]

I have a 2019 Air where the keyboard just stopped working. Not registering any input. When I restart it, it may start working for a short while then does it again.

Here's what I think is weird about this:

- If I connect an external keyboard via a USB-C hub, 2 out of 3 don't work either. However, they do type... somewhat. Some of the keys don't register at all, and some of the keys produce a completely different character. The third keyboard works fine. All are 3rd party. The only keyboard layout installed is US.

- The power button works fine.

So, is this a hardware issue (if it is, then what's up with external keyboards?) Is it a software issue? Anything to try other than opening the case and making sure that the connector cable is seated right?

I would suspect a hardware issue but then it doesn't explain why the 3rd keyboard works.

It doesn't make sense to have it professionally repaired, but at the same time I hate the idea of throwing out a device that could be fixed - it worked just fine before this started happening.

Any suggestions?

 

[DeltaMac]

Does your trackpad ever have problems?
Try the trackpad whenever you have keyboard problems.

 

[SnowCrocodile]

No trackpad problems.

 

[Ruggy]

I suggest you try resetting the SMC and hope that's the problem.

Shut down the Mac
Built in keyboard: Hold down Control+Option+Shift (not command so it's a sort of triangle)
Hold for 7-10 seconds then still holding, hold down power button for 7-10 seconds then release.
It should stay off. It's annoying because you get no feedback at all but normally when you push the power button it starts up and you get the Apple logo. If it starts up and shows the Apple loo it hasn't reset. You might need to do it a few times to get it right
So it stays off, wait a few seconds (yes I know it' vague but all of this is incredibly badly documented IMO) and when you are sure it's not going to restart on its on, then you can restart it.
It may very well solve your problem but it does sound like a hardware problem

 

[SnowCrocodile]

I suggest you try resetting the SMC and hope that's the problem.

Shut down the Mac
Built in keyboard: Hold down Control+Option+Shift (not command so it's a sort of triangle)
Hold for 7-10 seconds then still holding, hold down power button for 7-10 seconds then release.
It should stay off. It's annoying because you get no feedback at all but normally when you push the power button it starts up and you get the Apple logo. If it starts up and shows the Apple loo it hasn't reset. You might need to do it a few times to get it right
So it stays off, wait a few seconds (yes I know it' vague but all of this is incredibly badly documented IMO) and when you are sure it's not going to restart on its on, then you can restart it.
It may very well solve your problem but it does sound like a hardware problem

This didn't help, unfortunately.

However, after that I took off the back case, removed the small trackpad heat shield, removed and reattached the trackpad cable, re-assembled the laptop and completely reset the OS.

It's been working OK since last night.

I have a gut feel that this was somehow software related. While rebooting the MBA, I noticed that Caps Lock button would be responsive (light turning on and off when pressed) up to OS load and then just got stuck in one state. I think some corruption in OS blocked the keyboard operations.

Now I need to figure out what to do with a spare base specs 2019 MBA. She already bought a new one and is not going back as the battery life difference is amazing.

 

[Fishrrman]

"I noticed that Caps Lock button would be responsive (light turning on and off when pressed) up to OS load and then just got stuck in one state. I think some corruption in OS blocked the keyboard operations."

I've found that the caps lock key can behave differently during bootup and after login.

That is... during the boot process and until you've logged in... it behaves in the "default" manner (toggles caps lock off/on).

BUT... if you've done what I have -- that is, DISABLED the caps lock function (when I'm logged in) -- the caps lock will behave "as you've set it" after login.

But it continues to function as a normal "caps lock" key until your login is completed.

 

[SnowCrocodile]

It was starting to act up as the OS was loading. I was unable to login because the keyboard never worked.

It would work briefly after cold restart.

I’ll see if the laptop continues to work. Perhaps resetting the touchpad connector helped.