Mac use tips for Mac when booting the BIOS beep parsing

After the Apple machine power on, the bottom will carry out a series of self-test, if you can pass, back to hear the famous "boom ... ", and then boot the OS from openfirm.

If the self-test encountered a problem, will be issued 1 to 5 beeps, the length of the sound represents a different problem, the following is the meaning of these sounds, for reference:

On the earlier point of the machine, including: Blue White g3,pcig4, Big black G3PB (Bronze keyboard and Pismo)

1 beep: No memory or no memory bar detected.

2 beep: The memory stripe does not match. (Example: Inserted in a Edo)

3 beep: Memory does not pass self-test.

4 Beep: Other part of boot ROM bad checksum

5 beep: Boot ROM start part bad checksum

Compare the above models with new machines:

1 beep: no memory plugged in

2 beep: Memory mismatch

3 beeps: None of the memory is good.

4 beep: Boot ROM is out of video or the system preset module is broken

5 beep: The CPU is broken.