How to Reset the SMC on Mac

Whenever a Mac is behaving in an unpredictable and strange manner, its users look for simple solutions like rebooting it or performing a Safe Boot. If it doesn’t help, many Mac owners turn to resetting the system management controller (SMC) as a last resort. The article outlines common Mac issues that can be resolved with an SMC reset and details steps for performing it.

The SMC Functions

The SMC is responsible for many rudimentary hardware functions on Intel-based Macs:

  • Analyzing the use of the power button (power off, sleep, and accidental presses);
  • Responding to the opening and closing of the MacBook’s lid;
  • Battery performance management (charging, calibration, and remaining time estimation);
  • Thermal management;
  • Sudden Motion Sensor (SMS) management;
  • Controlling lightning levels;
  • Keyboard backlighting;
  • Display backlight management;
  • Controlling sleep mode.
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When to Reset the SMC

These are the signs suggesting that it’s time to reset the SMC:

  • Mac fans run at full speed even when the computer doesn’t perform CPU-and RAM-intensive tasks;
  • Erratic behavior of the keyboard backlight;
  • The power button is not responding to presses;
  • The status indicator is displaying incorrectly;
  • Battery is not charging;
  • Display is not responding to the changes of ambient light;
  • A USB-C port of a MacBook doesn’t recognize peripheral devices such as printers, card readers, and smartphones;
  • A Mac randomly enters the Sleep mode;
  • The overall sluggish performance of a Mac even under the low-intensity CPU use;
  • The inability to recognize an external display;
  • Bluetooth is not working;
  • Port illumination doesn’t turn off.

How to Reset the SMC

The choice of the appropriate approach to resetting the SMC hinges on the type of Mac owned by the user. Here is how to reset the SMC for newer Macs with non-removable batteries:

  1. Start by shutting down the Mac;
  2. Ensure that the MagSafe power adapter is connected to the Mac and a power source;
  3. Press and hold the Shift, Control, and Option keys while simultaneously pressing the power button. Hold the keys and the button for at least ten seconds;
  4. Release the keys and the button;
  5. Turn on the Mac by pressing its power button.

Owners of older portable Macs with removable batteries should do the following to reset the SMC:

  1. Turn off the Mac;
  2. Disconnect the MagSafe power adaptor;
  3. Take out the battery;
  4. Press and hold the power button for at least five seconds;
  5. Reinsert the battery;
  6. Connect the MagSafe power adaptor;
  7. Start the Mac by pressing the power button.

Those who have Mac desktop computers need to:

  1. Turn off the Mac;
  2. Disconnect the power cord;
  3. Wait 15 seconds or more;
  4. Reconnect the power cord;
  5. Start the Mac in five seconds.

iMac Pro computers released in 2012 and earlier require the following approach to making an SMC reset:

  1. Turn off the Mac;
  2. Disconnect the power cord;
  3. Press and hold the power button for eight seconds;
  4. Release the button and wait three more seconds;
  5. Start the Mac by pressing the power button.

Technically-savvy Mac users can perform a manual SMC reset by pressing and holding the SMC button for ten seconds. The button is located on the iMac’s Pro motherboard and can be accessed through the side panel.