Apple Self Repair Guides

Power Manager Reset

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If a unit crashes or experiences power problems, reset the power manager chip by pressing the rear power switch for 30-45 seconds.

If resetting the power manager chip does not solve the problem, reset the code for the power manager chip by removing all power sources and letting the unit sit for 10 minutes. (Take out the battery and disconnect the AC adapter and the internal backup battery.) This forces the PowerBook Duo to reload the power manager code from the system software.

RAM failure occurs (eight-tone error chord sequence sounds after startup chord)

Hardware failure occurs (four-tone error chord sequence sounds after startup chord)

Symptom Charts

Startup

1 Check RAM expansion card connection.

2 Replace RAM expansion card.

3 Replace logic board.

Note: When replacing the logic board, check that the EMI clips are securely attached to the CPU stiffener. The "CPU Stiffener" topic in Take Apart helps you locate and identify the two EMI clips. If both clips are not secure, replace the CPU stiffener.

1 Disconnect hard drive data cable and reboot system. If startup sequence is normal, reseat cable and retest.

2 Replace hard drive.

3 If the system is connected to an external floppy drive, disconnect drive and reboot system. If startup sequence is normal, reseat cable and retest.