If you are having significant issues after applying one of the recently released Intel-based Mac firmware updates (iMac, Mac mini, MacBook, MacBook Pro, Mac Pro), remember that you can revert to the original system firmware using the Firmware Restoration CD (version 1.2) [We noted the importance of this disc in May of this year).
Per Apple's instructions, you can only use this to restore the firmware after an interrupted or failed update. If your computer is in a crippled state after the update (unable to startup) the only option is to download the software and create the CD on another Mac or take the unit into an authorized repair center. To make things easier, Apple allows the CD to be created on both PowerPC- and Intel-based Macintosh computers.
In order to create a Firmware restoration disc, download the file:
then follow these instructions, from Knowledge Base article #303469:
- Open Disk Utility (located at /Applications/Utilities).
- Click the Burn icon or select the "Burn..." menu item from the Images menu.
- Navigate to where FirmwareRestorationCD.dmg is located (this is the file you downloaded), and click the Burn button.
- Insert a blank recordable CD.
- Click the Burn button to create the Firmware Restoration CD. The files are burned to the disc.
Now, to restore your Firmware:
- Ensure that the computer you are trying to restore is plugged into an AC outlet.
- Turn on the computer and continue holding down the power button until the LED blinks rapidly followed immediately by a successive series of blinks (3 quick blinks, 3 slow blinks, 3 quick blinks).
- Insert the Firmware Restoration CD while the lights are blinking, then release the Power button. You will hear a long tone once the recovery process has begun.