Resetting the Mac

System Management Controller (SMC)

MacBook (13 inch, Late 2008), MacBook Pro (15-inch, Early 2008), and MacBook Pro (17-inch, Early 2008)

1. If the computer is on, turn it off.
2. Disconnect the AC adapter and remove the computer’s battery.
3. Press and hold the power button for 5 seconds and then release the button.
4. Reconnect the battery and AC Adapter.
5. Press the power button to restart the computer

Note: Starting with MacBook Pro (Late 2008) and MacBook (Late 2008) models, you may instead use the reset method for MacBook Air (below) to reset the SMC.  All earlier models of MacBook and MacBook Pro must use the method described above, which involves removing the battery.

MacBook Air and MacBook Pro (Late 2008 and later)

1. If the computer is on, turn it off by choosing Shutdown from the Apple () menu.
2. Connect the power adapter to a working power source.
3. On the built-in keyboard, press (left) Shift-Control-Option along with the power button once.
4. Wait 5 seconds and press the power button to start the computer.

Note: You must use the keys on the left side of the built-in keyboard.

You should only perform an SMC reset when the MacBook Air or MacBook Pro (17-inch, Early 2009) has been properly shutdown. This prevents issues from occurring to the file system.

While the power adapter does not need to be connected to reset the SMC, it may be necessary in situations where the battery needs charging or if the computer has been without power for an extended period of time. You can also visually check the SMC reset by observing the LED on the adapter. It will momentarily turn off as the SMC resets.

PRAM and NVRAM

1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.

Your computer’s PRAM and the NVRAM are reset to the default values. The clock settings may be reset to a default date on some models.