System Management Controller (SMC)


What is the System Management Controller (SMC)?

The System Management Controller is a lower level tool used by Apple computers with Intel processors. It manages many essential operations and elements of your computer, including temperature, power, battery charging, video modes, the sleep and wake functions, indicator lights, and the internal fans. Reseting your SMC can be a very useful tool when you begin experiencing issues with your machine. There are many common issues that can be linked with the System Management Controller, such as:

  • Overly high fan speeds
  • Malfunctioning backlighting on the keyboard
  • Faulty indicator lights
  • Display backlight issues
  • Any issue relating to powering the unit
  • Battery and charging issues
  • Unresponsive sensors
  • Issues relating to use of external monitors or displays
  • Slow performance when the CPU is not being stressed




Resetting the SMC for iMac, Mac mini and Mac Pro

  1. Shut down the computer
  2. Unplug the computerís power cord
  3. Wait 15 seconds
  4. Attach the computerís power cord
  5. Wait 5 seconds, then press the power button to turn on the computer

Resetting the SMC for Apple laptops with a REMOVABLE battery

Note: Apple laptops having a battery you can remove (with no tools) include: MacBook Pro (Late 2008) and earlier and MacBook (Mid 2009) and earlier. Learn about removing the battery on MacBook and MacBook Pro.

  1. Shut down the computer
  2. Disconnect the MagSafe power adapter from the computer (if connected)
  3. Remove the battery
  4. Press and hold the power button for 5 seconds
  5. Release the power button and reconnect the battery and MagSafe power adapter
  6. Press the power button to turn on the computer




Resetting the SMC for Apple laptops with a BUILT-IN battery

Note: Apple laptops having a built-in battery (requiring tools) for removal include: MacBook Pro (Early 2009) and later, all models of MacBook Air, and MacBook (Late 2009) and later.

  1. Shut down the computer
  2. Plug in the MagSafe power adapter to a power source (connecting it to the Mac if it is not already connected)
  3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time
  4. Release all the keys and the power button at the same time
  5. Press the power button to turn on the computer
Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.