Chapter 5 Troubleshooting 87
Using Apple Hardware Test
You can use Apple Hardware Test to help determine if there is a problem with your
iMac computer’s hardware.
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 Insert the Mac OS X Install Disc 1 that came with your iMac.
3 Restart your iMac and hold down the “D” key as it starts up.
4 Select the language appropriate for your location when the Apple Hardware Test
language chooser screen appears.
5 Press the Return key or click the right arrow button.
6 When the Apple Hardware Test main screen appears (after about 45 seconds), follow
the onscreen instructions.
7 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.
For more information about Apple Hardware Test, see the Apple Hardware Test Read
Me file on the Mac OS X Install Disc 1.