If there is an installation issue
If the update to your firmware was interrupted, your computer will beep 9 times when restarting (3 short, 3 long, 3 short) and the screen will be black. Your computer will attempt to recover by itself. It can take up to 30 seconds for your computer to restore the EFI Firmware to the previous version. Do not unplug your computer during this process. Your computer will restart by itself when the EFI Firmware is restored. After you computer restarts again, try installing again by opening the Firmware Updater application, which is located in the Utilities folder (/Application/Utilities). Then go to Step 4 above.
If you computer does not automatically recover, contact AppleCare for more information.
