Apple Hardware Test is a diagnostic tool for detecting problems with your computer's internal hardware components such as the logic board, memory, modem, video RAM, and Apple's AirPort card. It does not check externally connected hardware components such as USB drives or Firewire devices; it does not check non-Apple devices such as PCI cards from other vendors.
Before using Apple Hardware Test, disconnect external devices (excluding Apple keyboard, mouse, display, and speakers), and remove any non-Apple cards that were not included in Apple's shipping configuration of your system.
Apple Hardware Test does not check your computer for problems with the Operating System (OS) or other software related problems such as application or extension conflicts.
To use the Apple Hardware Test CD, restart your computer while holding down the C key until the "Loading..." icon appears, then you may release the C key. Loading will take approximately 45 seconds. Apple Hardware Test's main screen will appear. Follow the on-screen instructions and recommendations.
Apple Hardware Test for Power Mac version 1.1 is distributed only with the Power Mac G4, and will not work with any other computer.
If you suspect your computer has a hardware problem, the information provided by Apple Hardware Test can help identify the problem. If Apple Hardware Test detects a problem, an error code will be displayed. Please make a note of the error code before pursuing support options. If no hardware failure is detected, the problem may be software related.
Known issues
Apple Hardware Test cannot be used when a mouse is directly connected to the USB port on the display or on the Power Mac G4. Please connect the mouse to a USB keyboard.
The Apple Hardware Test CD will not be ejected on a Power Mac G4 when the Restart/Shutdown button in Apple Hardware Test us clicked. Either manually eject the CD, or use Mac OS to eject the CD.
It may take significantly more time than indicated (on the Apple Hardware Test screen) to run the Extended Test on a Power Mac G4 with more than 512 MB of RAM installed; durations between 18 and 20 minutes have been observed.
AppleCare Recommendations
Apple Hardware Test is one of several tools and procedures you can use when your Macintosh is having trouble. Here are some steps you can follow to help resolve problems. Please back up your data before performing any of these steps.
1. Turn the computer off and on.
You can often eliminate problems by selecting the "Shut Down" option from the Special menu to fully shut down the CPU, then restarting your system.
2. Check cables, peripherals, and user controls.
Shut down your computer. Then disconnect and reconnect all cables. Disconnect all peripherals (such as printers, scanners, cameras and external mass storage devices) to see if they are causing conflicts with your system. Adjust user controls on your monitors and other peripherals to see if this helps.
3. Turn off system extensions.
Restart your system while holding down the Shift key until the following message appears: "Extensions disabled." Then release the key. This turns off system extensions that often cause conflicts. If this solves your problem, use the Extensions Manager to turn off extensions that may be causing the problem.
4. Rebuild the desktop.
Restart your system while holding down the Option and Command keys. Click OK when asked if you want to rebuild the desktop.
5. Start up from the system CD that shipped with your computer.
Start your system from the system CD by holding down the C key until you see the smiling Mac face. If the system works properly when started (booted) from the system CD, you can generally assume that the problem relates to the software which is installed on your computer.
6. Start up from the Apple Hardware Test CD, and run the Quick and Extended Tests.
If the system does not work properly when started (booted) from a known-good system CD (Step 5), you can generally assume that the problem relates to your computer's hardware components. The Apple Hardware Test CD can often be used to start up your computer even if it will not boot into the Mac OS. If Apple Hardware Test passes both the Quick Test and the Extended Test, the problem may be software related. If Apple Hardware Test detects a problem, make a note of the error code and contact Apple (Step 9).
7. Refer to Mac OS Help Center and the Internet for assistance.
The Mac OS help system under the Help menu in the Finder includes a wealth of technical information. Apple's Knowledge Base, and other resources for technical help and support are available 24 hours a day at www.apple.com/support.
8. Re-install Mac OS.
In many cases, a clean installation of the Mac OS will fix recurring problems. Back up any data before reinstalling. Please follow the instructions in your user manual or on your Restore CD to reinstall the Mac OS.
9. Contact Apple Service and Support for assistance.
If these steps don't help resolve the problem, please review the service and support material that accompanied your computer for information on how to contact AppleCare for further assistance. Apple reserves the right to change telephone hours at any time.
Note: Wireless Internet access requires an Internet service provider (fees may apply) and AirPort (or AirPort-compatible) wireless Ethernet card and base station. Some ISPs are not compatible with AirPort. For more information, see technical document 106590: "AirPort: Requirements for Wireless Internet Access"