- Your computer must be started up to a version of Mac OS X v10.5.8 or Mac OS X v10.6.4.
Note: If you do not wish to update the operating system on your computer, you can install one of these operating system versions on an external drive and start up from that device.
- Your computer's power adapter must be connected to the computer and plugged in to a working power source, or the battery must be at least 25% charged.
- If the computer's battery is not charged or if the power adapter is not powering the computer, reset the SMC to allow these power adapters to operate temporarily while you apply the update.
When your computer restarts, a gray screen will appear with a status bar to indicate the progress of the update. Your computer's fans may run at full speed during the update but should return to normal speed once the update completes. Do not disturb or shut off the power on your computer during this update.
When the update has been applied, you can restart to a previous version of Mac OS X if you would like.
Find out more about applying SMC updates for Mac OS X v10.5.8 (Leopard) or more about applying SMC firmware updates for Mac OS X v10.6.4 or later (Snow Leopard).
Learn more about power adapter compatibility across Apple computers and using the right power cord for your computer (United States only), and about troubleshooting tips for all MagSafe adapters.