Technical information

m There may be a problem with the information stored in the area called parameter RAM (PRAM) or
nonvolatile video RAM (NVRAM). Reset the NVRAM and the PRAM (also called “zapping the PRAM”).
When you reset the PRAM and NVRAM, the settings on most of your computer’s control panels
revert to their defaults (original, standard settings). You may want to check the settings in your
control panels for memory, networking, and monitors, and any aspect of your work that seems
affected after you reset PRAM and NVRAM.
Follow these steps to reset the PRAM and NVRAM:
1 Shut down your computer by pressing the Power key (π) and then clicking Shut Down.
2 Make sure the Caps Lock key is not engaged.
3 Position the fingers of your left hand on these keys: Command (x), Option, and R. Locate the
P key, so you can find it quickly for step 4.
4 Press the Power key (π) to turn on your computer. Immediately after you hear the startup
sound, press and hold down the Command (x), Option, R, and P keys simultaneously.
5 When you hear the startup sound twice, release the keys. Then immediately press and hold
down the Shift key to start up with extensions turned off. Release the Shift key when you see the
message “Extensions off ” in the “Welcome to Macintosh” box.
If you don’t see the “Extensions off ” message, wait until startup is complete, then press and hold
down the Shift key while you choose Restart from the Special menu. Continue to hold down the
Shift key until the message appears.
6 If the computer shuts itself off, press the Power (π) key to turn it back on.
7 Open the System Folder, then open the Preferences folder.
8 Drag the Display Preferences icon to the Trash.
9 Restart the computer without holding down the Shift key.
The computer starts up with extensions turned on again.
10 If you had specified special settings in any control panels, open those control panels to respecify
the settings you want.
Chapter
Twelve
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