Desktop Macintosh: Hold power button to reset

  • Last Modified: August 01, 2008
  • Article: HT2322
  • Old Article: 88330

Summary

On some models of iMac, eMac, Mac mini and Power Mac G5, the computer's power button replaces the power reset button and programmer's switch.

The following computers do not have a power reset button or a programmer's switch (NMI button, also known as a NMI or nonmaskable interrupt button). You use the power button for these functions.

  • iMac (Flat Panel) - all models
  • iMac G5 - all models
  • eMac - all models
  • Mac mini - all non-Intel-based models
  • Power Mac G5 - all models

Products Affected

Power Mac G5, Power Mac G5 (Early 2005), Power Mac G5 (June 2004), Power Mac G5 (Late 2004), Power Mac G5 (Late 2005), eMac, Mac mini, iMac (17 inch, Flat Panel), iMac G5 (17-Inch iSight), iMac G5 (17-Inch), iMac G5 (20-Inch iSight), iMac G5 (20-Inch), iMac G5 ALS (20-Inch), iMac G5 ALS (17-Inch)

Sleep

Press the power button for one second to put the computer to sleep. To wake the computer from sleep, press the power button for less than one second or press any key on the keyboard.

Shut down

To shut down the computer, select Shut Down from the Apple menu (or from the Special menu if you are using Mac OS 9). You will be prompted to save any unsaved documents.

If the computer is unresponsive, you can force the computer to shut down by pressing the power button and holding it for at least 5 seconds.
Important: If you do this, information in any unsaved documents may be lost.

Firmware updates

From time to time, Apple has provided firmware updates to address certain issues that cannot be addressed in updates to software. On earlier computers, the programmer's switch was used to install a firmware update.

Follow these steps in the event that a firmware update is needed for these computers with no programmer's switch:

  1. After downloading and running the firmware update, shut down the computer.
  2. Wait until the computer is shut down and the power light is off.
  3. Press and hold the power button for several seconds.
  4. The computer will signal that a firmware update is ready to be installed by making a steady tone and the power button light will quickly flash several times for several seconds.
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