MacBook – MBP built in keyboard unresponsive until complete shutdown

keyboardmacbook pro

MacBook Pro (Retina, 15-inch, Mid 2015), running macOS Catalina 10.15.5.

Sometimes while working, the built-in keyboard becomes completely unresponsive, the only button that works is the power button. Logging-off, sleeping etc. does nothing, only shut down and fresh boot (with the chime) removes the issue.

While the issue is happening, the Caps Lock light is turned on.

Touchpad works fine, and plugging external USB keyboard also works (but doesn't unlock the built-in keyboard).

Mouse Keys, all this stuff is turned off.

I noticed, but have no proof, that this happens when I'm pressing various left-side modifier keys: shift, alt, ctrl, cmd, tab.

Is this a hardware issue? A software issue? A hidden shortcut? Is there some kind of logging that can be turned on to watch for this kind of things?

Best Answer

This is a hardware issue and more than likely you need to have the keyboard (top case) replaced.

The keyboard is on the USB bus; if you look for it in the device tree of the system report, you’ll find it there. The fact that it stops working after a while says yo have a failing component - what exactly is impossible to know without putting hands on with proper diagnostic gear.

We know that it’s not your USB bus because you can plug in a different keyboard and it works - so the USB bus on your logic board is fully functional.

Hidden shortcut? No. With all of its complexity even modern computers are still pretty binary - it either works or it doesn’t. There’s no setting to tell your keyboard to only work for a little while then stop, then start again after a reboot. Hardware functionality becomes intermittent when it’s in the process of failing (or failed).

You mentioned that the issue happens when your Caps Lock key is engaged. If so, you may have narrowed down the issue however, the resolution is still, unfortunately the same - replace the keyboard.

Keyboard key stuck or not being recognized; how to fix

Related Solutions

Is it possible to display the current state of modifier keys

There is one native solution I can think of, and that's to show the Keyboard Layout window. This can be accessed through the input menu in the menu bar*, and will show you all keys and their current states. A bonus to this for normal circumstances is that you can see where option and shift-option special characters are mapped.

Another possible solution involves a third-party app such as Keyboard Maestro. If you create a macro triggered by the press of a modifier key, you can tell it to, say, display a Growl notification with a relevant message. I'm not exactly sure how you'd want to do this, or what exactly you'd want it to do in the first place, but many of these programs have tons of options.

*To enable this, go to System Preferences > Keyboard > "Show Keyboard and Character Viewers in menu bar"

Modifier key settings not sticking

Try uninstalling any keyboard or pointing device drivers. Or delete ~/Library/Preferences/ByHost/.GlobalPreferences.*.plist and restart.

You can also use PCKeyboardHack to remap caps lock. Other modifier keys can be remapped with KeyRemap4MacBook:

<?xml version="1.0"?>
<root>
  <!-- <devicevendordef>
    <vendorname>KINESIS</vendorname>
    <vendorid>0x05f3</vendorid>
  </devicevendordef>
  <deviceproductdef>
    <productname>ADVANTAGE</productname>
    <productid>0x0007</productid>
  </deviceproductdef> -->
  <item>
    <name>swap_command_and_control</name>
    <identifier>swap_command_and_control</identifier>
    <!-- <device_only>DeviceVendor::KINESIS, DeviceProduct::ADVANTAGE</device_only> -->
    <autogen>__KeyToKey__ KeyCode::COMMAND_L, KeyCode::CONTROL_L</autogen>
    <autogen>__KeyToKey__ KeyCode::COMMAND_R, KeyCode::CONTROL_L</autogen>
    <autogen>__KeyToKey__ KeyCode::CONTROL_L, KeyCode::COMMAND_L</autogen>
  </item>
</root>

Best Answer

Related Solutions

Is it possible to display the current state of modifier keys

Modifier key settings not sticking

Related Question