I recently spilled water on my computers keyboard, and as a result the left shift key seems to be stuck in the on position. This means that the system always boots into safe boot unless I hold down the option key. I have managed to change my password to one which is all caps and once I login I use keyremap4mac but it is still very annoying. Is there anyway which I can remap the keyboard during boot? Possibly with a startup bash script or something similiar? If that is not possible is there any way to use a script to bypass safe boot? I was planning on installing a new bootloader anyway in order to dual-boot linux, I don't know if this will help. Advice is appreciated.

  • What type of Mac are you using?
    – nohillside
    Commented Nov 14, 2013 at 13:23
  • 1
    I think your best bet is to just get a new keyboard. Or Unplug it when booting, unless you are talking about a laptop
    – markhunte
    Commented Nov 14, 2013 at 14:05

1 Answer 1


You could enable a firmware password. When a firmware (EFI) password is active it prevents modifier keys during the boot process unless you first disable the firmware password. Apple's KB article detailing this behavior - HT1352

I'm going to assume that you can't boot to your recovery partition, or an installer disc, thanks to the stuck shift key. Typically you would enable the firmware password from either of these options, however it's still possible to do from the OS.

To enable the firmware password while inside your OS, 10.7 or newer:

  1. Enter the following string in Terminal. This enables the debug menu in Disk Utility. defaults write com.apple.DiskUtility DUDebugMenuEnabled 1
  2. Open Disk Utility and choose "Show every partition" from the Debug menu.
  3. Your Recovery partition should now be visible on the left side of Disk Utility, select and click Mount to mount it in your system.
  4. In Terminal, enter the copy & paste the following command to load the Recovery disk image. open /Volumes/Recovery\ HD/com.apple.recovery.boot/BaseSystem.dmg
  5. The Recovery disk should open in a new window, browse to it's /Applications/Utilities folder.
  6. Locate the Firmware Password application and double click to launch it.
  7. Follow the on-screen instructions to enable a firmware password. I would recommend keeping this password very simple and easy for you to remember. The firmware password CAN be bypassed but the difficulty of doing so varies between Macs.

If your version of Mac OS X is 10.6 or older:

  1. While booted to your OS, insert the gray restore disc labeled "Install Mac OS X".
  2. Open Terminal and copy & paste the following command, this will open a window showing the Utilities folder from the system installer. open /Volumes/Mac\ OS\ X\ Install\ DVD/Applications/Utilities
  3. Double click the Firmware Password application to launch it.
  4. Follow the on-screen instructions to enable a firmware password.
  • If I set up a firmware password will that mean I can no longer boot into the recovery partition or is there still a way to do this?
    – stmfunk
    Commented Nov 14, 2013 at 15:27
  • Without the damaged keyboard, yes, OPTION is the only key that works with a firmware password. When OPTION is detected at boot you will be asked to enter the firmware password, at which point you will see the Startup Manager and your bootable partitions (Recovery & Macintosh HD). With shift being stuck though the Mac sees both SHIFT & OPTION being held, which it will ignore regardless of the firmware password since it's not a valid boot modifier. Hopefully that helps.
    – Mr Rabbit
    Commented Nov 14, 2013 at 15:41
  • @stmfunk I don't know of a way to set the startup disk to be the built in Recovery partition from within the OS, but you could create a USB Recovery Disk using info found elsewhere on here, and then set that to be the startup disk from within System Preferences.
    – Mr Rabbit
    Commented Nov 14, 2013 at 15:48

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