Apple iMac (Intel-based, Late 2006) - Manual (Page 42)

42 Chapter 4 Problem, Meet Solution
If your iMac freezes during startup or you see a flashing question mark
 Wait a few seconds. If your iMac doesn’t start up after a brief wait, shut it down
by pressing and holding the power (®) button for 5 or 6 seconds, until your iMac
shuts down. Then hold down the Option key and press the power (®) button again
to start up your iMac. When your iMac starts up, click the hard disk icon and then
click the right arrow.
 After your iMac starts up, open System Preferences and click Startup Disk. Select a
local Mac OS X System folder.
 If the problem occurs frequently, you may need to use Disk Utility (on the Mac OS X
Install Disc 1 that came with your iMac) or reinstall your system software (see
“Reinstalling the Software That Came with Your iMac” on page 48).
If your iMac won’t turn on or start up
 Make sure the power cord is plugged into your iMac and into a functioning
power outlet.
 Press the power (®) button and immediately hold down the Command (x), Option,
P, and R keys until you hear the startup sound a second time.
 If you recently installed memory, make sure that it is correctly installed and that it is
compatible with your iMac. Check whether removing the memory you installed
allows your iMac to start up (see page 33).
 Unplug the power cord and wait at least 30 seconds. Plug the power cord back in
and press the power (®) button again to start up your iMac.
 If you are still unable to start up your iMac, see “Learning More, Service, and Support”
on page 51 for information about contacting Apple for service.