It's a 2011 MacBook pro and the a and c keys are not working on both the built-in keyboard and the usb keyboard.

Because of this i can't bypass the firmware login screen. Now the weird thing is that that cmd + a works (select all) so the key is being recognized, but a by itself doesn't.

Any ideas?

  • is it only the a and c keys?
    – dwightk
    Apr 2, 2014 at 15:20
  • As far as i can tell
    – DGDD
    Apr 2, 2014 at 15:43
  • How about option a and option c? (å and ç on US layout) Apr 2, 2014 at 16:13
  • That does nothing
    – DGDD
    Apr 2, 2014 at 19:31
  • Most likely there is/are key(s) stuck on the internal keyboard. To diagnose, disconnect the keyboard from logic board and use an external keyboard.
    – Allan
    May 6, 2018 at 5:53

1 Answer 1


You can start by rebooting into safe mode as a troubleshooting step. Restart and hold down the shift key, when booted into safe mode you can test the keys:

Delete the preference file which can be found here /Library/Preferences/com.apple.keyboardtype.plist

Restart normally

  • Cant boot into safemode because of firmware password. Firmware password appears instantly upon boot
    – DGDD
    Apr 2, 2014 at 18:05
  • Does your computer have a removable RAM? If so then you can take out one RAM stick and boot the computer by holding down CMD+ALT+P+R and allow the computer to reboot 3 times which should clear the firmware password.
    – Maximus
    Apr 3, 2014 at 10:14
  • I tried but it turns out that only works on pre 2010 macs.
    – DGDD
    Apr 4, 2014 at 16:13

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