Chapter 5 Troubleshooting 73
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:
1Disconnect all external devices from your iMac except the keyboard and mouse.
If you have an Ethernet cable connected, disconnect it.
2Insert the Mac OS X Install Disc 1 that came with your iMac.
3Restart your iMac and hold down the “D” key as it starts up.
4Select the language appropriate for your location when the Apple Hardware Test
language chooser screen appears.
5Press the Return key or click the right arrow button.
6When the Apple Hardware Test main screen appears (after about 45 seconds), follow
the onscreen instructions.
7If 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.