How to Reset the System Management Controller SMC

The System Management Controller (SMC) is a chip on the logic board that controls all power functions for your computer. If your computer is experiencing any power issue, resetting the SMC may resolve it. The SMC controls several functions, including:

  • Telling the computer when to turn on, turn off, sleep, wake, idle, and so forth.
  • Handling system resets from various commands.
  • Controlling the fans.

Note that resetting the SMC does not reset the PRAM. Resetting the SMC will not resolve issues in which your computer is unresponsiveā€”in these situations, restarting your computer will generally suffice. If your computer isn't responding, perform these steps one at a time, in this order, until the issue has been resolved:

  1. Force Quit (Option-Command-Escape).
  2. Restart (Control-Command-Power).
  3. Force Shut Down (press the power button for 10 seconds).

Resetting the SMC can resolve some computer issues such as not starting up, not displaying video, sleep issues, fan noise issues, and so forth. If your computer still exhibits these types of issues after you've restarted the computer, try resetting the SMC.

To reset the SMC on an iMac (24-inch)

  1. From the Apple menu, choose Shut Down (or if the computer is not responding, hold the power button until it turns off).
  2. Unplug all cables from the computer, including the power cord.
  3. Wait at least 15 seconds.
  4. Plug the power cord back in, making sure the power button is not being pressed at the time.
  5. Reconnect your keyboard and mouse to the computer.
  6. Press the power button on the back to start up your computer.

Note: The iMac (24-inch) does not have a button on the main logic board for resetting the SMC, which eliminates the need to remove the computer's cover to reset it (as required for some other models).

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  • Larissa
    Have to periodically reset SMC on imac?
    10 years ago
  • max
    How to restart smc on iMac?
    10 years ago
  • jali rinne
    How to reset imac 24 inch?
    10 years ago
  • shannon
    How to reset smc for powermac g4?
    9 years ago
  • tarquinia
    How reset smc chip on imac?
    9 years ago
  • Kaarina
    How to resset an imac 20 inch?
    9 years ago
  • amethyst
    How to reset pram, 24 inch imac?
    9 years ago
  • george wendland
    How to reset smc g4 17in domed imac?
    3 years ago

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