There is a power-on self test that resides in the ROM of the Power Mac G4. This test automatically runs whenever the computer is powered on after being fully shut down (the power-on self test does not run if the machine is only restarted). If a problem is detected during the test, you will not hear a normal startup chime.

If you do not hear the normal startup chime, the system will beep as explained below:

• 1 Beep: No RAM is installed or detected
• 2 Beeps: Incompatible RAM types are installed (for example both SDRAM and EDO installed).
• 3 Beeps: No RAM banks passed memory testing.
• 4 Beeps: No good boot images are detected in the boot ROM (and/or there is a bad sys config block)
• 5 Beeps: The processor is not usable