Apple iMac (17-inch Mid 2006) User Manual
Page 124
iMac (17-inch Mid 2006/Late 2006 CD) Troubleshooting — General Info
124
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 unresponsive—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:
Force Quit (Option-Command-Escape).
Restart (Control-Command-Power).
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
From the Apple menu, choose Shut Down (or if the computer is not responding, hold the
power button until it turns off).
Unplug all cables from the computer, including the power cord.
Wait at least 15 seconds.
Plug the power cord back in, making sure the power button is not being pressed at the time.
Reconnect your keyboard and mouse to the computer.
Press the power button on the back to start up your computer.
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