Technical information

General / Power-On Self Test -
2
Troubleshooting
PowerBook (FireWire)
Power-On Self Test
There is a power-on self test that resides in the ROM of the
PowerBook (FireWire). 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 computer is
only restarted).
If a problem is detected during the test, you will not hear a
normal startup chime. Instead, the system will beep as
explained in the Power-On Self Test Beep Definitions chart.
Power-On Self Test Beep Definitions
Beeps Definition
1 beep No RAM is installed or detected.
2 beeps EDO memory is installed. The PowerBook (FireWire)
ships with SDRAM SO-DIMMs and does not accept EDO
memory.
3 beeps No RAM banks passed memory testing.
4 or 5 beeps Bad checksum for the remainder of the boot ROM. The
ROM (which is located on the microprocessor module)
is bad.