Apple Computer Beep Codes
Tone(s) = Description
- 1 tone, a 5-second pause, repeat = No RAM installed
- 3 successive tones, a 5-second pause, 3 successive tones = RAM does not pass data integrity check
- 1 long tone when holding down the power button = Firmware upgrade in process.
- 3 long tones, 3 short tones, 3 long tones = Firmware restoration from CD in process.
The power on self-test resides in the ROM of the computer. This test runs whenever the computer is turned on after being fully shut down (the power-on self-test does not run if the computer is only restarted).
If a fault is detected during the test, you will not hear a normal startup chime. Instead, the system will beep as explained below. If you experience one of these beeps, you may call your Apple Authorized Service Provider for additional troubleshooting assistance.
- 1 beep = no RAM installed
- 2 beeps = incompatible RAM types
- 3 beeps = no good banks
- 4 beeps = no good boot images in the boot ROM (and/or bad sys config block)
- 5 beeps = processor is not usable
In addition to the beeps, on some computers the power LED will flash a corresponding number of times plus one. The LED will repeat the sequence after approximately a 5-second pause. The tones are only played once.
Note: In this case, a flash is considered to be 1/4 second or 250 ms or greater in length.