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About the SMC Firmware Updates

SMC Firmware Updates refer to the System Management Controller (SMC) firmware update for Intel-based computers. The SMC is a micro-controller on the logic board that controls the power functions for your computer. The SMC controls various functions, including:

  • Power and thermal management, the Sleep LED, and battery.
  • Controlling the fans, supporting Sudden Motion Sensor, Ambient Light Sensor (ALS), and the power switch.

Tip: Print or write down these instructions before you begin installing the update.

Note: Some USB and FireWire devices may prevent firmware updates from installing correctly; disconnect non-essential devices and use only an Apple keyboard and mouse to apply the update.

Determine if an update is available for your computer.

  1. Refer to EFI and SMC firmware updates for Intel-based Macs to determine if an update is available for your computer.  You can also choose Apple () > Software Update to see if an EFI update is available for your computer.

Install the firmware update application.

  1. Close any open applications, then download the SMC Firmware Update available for your computer from Apple Downloads.
  2. The downloader will place the disk image with an installer in your downloads folder or the location specified in the General tab under Safari > Preferences. If you downloaded the disk image via Safari, Safari will notify you that an application is in the image. Click OK to continue.

Use the firmware update application to install the SMC Firmware Update.

  1. If "Open safe files after downloading" is enabled in Safari preferences, the disk image file will mount by itself. If that preference is not enabled in Safari, double-click the disk image to mount it.
  2. Double-click the SMC Update.pkg file.
  3. Click Continue when the Welcome screen appears.
  4. Click Continue after the information screen provides you with more detail about the update. 
  5. If a Software License Agreement appears, click Continue.  Agree to its terms by clicking Agree.
  6. A "Standard Install" screen will appear.  This will install the SMC Firmware Update software in a temporary area on your hard disk.  This file will be deleted automatically when the update is complete.  Click Install.
  7. Enter your administrator password and click OK.
  8. Click Continue Installation when a dialog box appears, informing you that your computer needs to restart to complete the installation.
  9. Click Restart to proceed with the SMC Firmware update when an Installation Complete dialog appears. 
  10. The screen will turn black and may remain that way for several seconds.  A long tone will play.  The computer will restart with a gray screen and an Apple logo; a progress bar at the bottom of the screen will indicate that the SMC firmware update is running.
  11. Your computer's fans will run at full speed during the update but should return to normal speed once the update completes. Important: Do not interrupt the update process. Note: If a progress indicator does not appear and your fans do not run at full speed, it is unlikely the update is being applied to your computer. Choose Software Update from the Apple () menu and try running the update again, or download and reapply the update manually.
  12. The computer will restart again once the firmware update is complete.

Note: This update requires a Macintosh-formatted disk or partition.

Last Modified: Aug 3, 2012
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  • Last Modified: Aug 3, 2012
  • Article: HT4117
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