Checking for a Hardware Problem
If you suspect a hardware problem, use the Apple Hardware Test application to help
determine if there’s a problem with one of the iMac components.
To use Apple Hardware Test:
1
Disconnect all external devices from your iMac, except the keyboard and mouse.
If you have an Ethernet cable connected, disconnect it.
2
Restart your iMac while holding down the D key.
3
When the Apple Hardware Test chooser screen appears, select the language you
want to use.
4
Press the Return key or click the right arrow button.
5
When the Apple Hardware Test main screen appears (after about 45 seconds), follow
the onscreen instructions.
6
If Apple Hardware Test detects a problem, it displays an error code. Make a note of the
error code before pursuing support options. If Apple Hardware Test doesn’t detect a
hardware failure, the problem may be software-related.
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Chapter 4
Problem, Meet Solution
Important:
If the Apple Hardware Test window doesn’t appear after restarting, hold
down the Command (x), Option, and D keys and restart the computer to access the
Apple Hardware Test software from the Internet. Your computer must be connected to
a network that has access to the Internet.