How To Run The Apple Hardware Test
To run the Apple Hardware Test on your Intel-based Mac, follow the steps given below:
1. Disconnect all the external devices like printers, Flash drives, scanners, hard drives and so on (except mouse and keyboard) from your computer.
2. Insert the Mac OS X Setup Disc 1 (If you have OS X 10.5.4 or earlier) or Mac OS X Setup Disc 2 (If you have OS X 10.5.5 or later) into the optical disc drive.
Note: The Mac OS X Install Discs should be included with your Mac.
3. Restart your computer and press and hold down the D key on your keyboard before the startup screen comes up.
4. The Apple Hardware Test will start in a couple of minutes. Once it is started, it will inspect your computer’s hardware configurations. This process will take a little moment.
5. When the hardware inspection completes, you will be able to select a language of your preference on the screen. After selecting the language, click on the right arrow or hit the Return key on your keyboard.
6. The Apple Hardware Test screen appears where you can choose the type of test(s) to perform.
7. If you wish to perform all of the basic tests, hit the T or Return key or click the Test button on the screen. To perform a thorough test, select “Perform extended testing" before you click on the Test button. After you click on the Test button, the test will start and in a little moment, the test results will display in bottom right-hand side window.
8. To see specific information about your Mac, go to the Hardware Profile tab on the Apple Hardware Test console. When you are in the tab, select a subject on the left to see particular information.
9. To exit the Apple Hardware Test, click on the Restart or Shutdown button.