Apple Mac mini (Early 2006) - Manual (Page 65)

Chapter 4 Troubleshooting 65
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.
Locating Your Product Serial Number
You can find the serial number on the bottom of your Mac mini. You can also use
System Profiler to find the serial number. Choose Apple () > About This Mac from the
menu bar, and then click More Info. Click the Hardware disclosure triangle to view the
serial number.