PowerBook G4 (1GHz/867MHz) (Ashley Pomeroy, Wikimedia Commons, CC BY-SA 4.0)
Fault-finding on the four PowerBook G4 (Titanium) models. Apple's charts list the steps in order: try each, test, and refit the original part before moving on.[1][2][3] The charts for the DVI and 1 GHz models are the fullest; the first model's Service Source carries Apple's 2001 troubleshooting articles. Disassembly is on PowerBook G4 (Titanium) General Maintenance.
Battery, adapter, power manager, keyboard, DC-in board, logic board
Apple's order (DVI and 1 GHz): remove peripherals; press the battery button and check that at least one LED lights steadily; fit a known-good adapter of the right type and check that the DC plug lights; try without the battery; if Caps Lock lights, hold the power button six seconds and restart; reset the power manager with a non-metallic tool on the button left of the power button; check the power button cable; disconnect the keyboard; remove extra RAM and the AirPort Card; check and then replace the DC-in board; replace the logic board[1][2]
DC plug does not light
DC-in board
With a known-good adapter, replace the DC-in board[1][2]
Dead, or starts only intermittently, on the first model
Flat backup battery
Unplug the backup battery; owners have revived machines this way[4][5]
Adapter light green with no battery; amber then off with the battery fitted; fans run for a second (DVI)
DC-in board or logic board
joshc's machine was not fixed by disconnecting the backup battery or resetting the power manager; the forum suspected the DC-in board or logic board[6]
Fan and drive run, Caps Lock lights, but no chime or video
Power manager, logic board
Reset the power manager, wait five seconds and press the power button; then replace the logic board[1][2]
One beep at power-on
No RAM found (there is none on the logic board)
Refit the original or known-good memory; then the logic board[3][1]
Remove the upper module and restart; replace the lower module; then the logic board[3][1]
Four beeps
Bad boot ROM checksum
The ROM is on the logic board; after trying known-good memory, replace the logic board[3][1]
Flashing question mark
Drive, flex cable, system
Start from the restore disc; check and repair the drive in Disk Utility or Disk First Aid; reinstall the system; reseat the hard drive flex cable; replace the drive[1][2]
Mac OS 9 will not install from a retail CD
Disc too old for the machine
Mighty Jabba needed the machine's original restore CD[4]
Disconnect peripherals; check the battery is fully in and charged; keep the vents clear and the machine off soft surfaces; check the fan and its cable; check the heat exchanger seating (new thermal material if it was separated); try a known-good adapter with the battery out and watch the DC plug light; then the DC-in board and logic board[1]
Shuts down just after startup
Battery, logic board
Check the battery and its connection; replace the logic board[1]
Kernel panic or "built-in memory test has detected an error"
Memory
Remove the upper module and retest; replace modules one at a time; run Apple Hardware Test in loop mode[1]
L2 cache missing or reported failed (400 MHz)
Cache SRAMs, solder joints or processor
Ivan Holmes's machine has two Samsung K7A403600M-QC20 SRAMs; reflowing them did not cure it[7]
No picture or a dim picture, machine otherwise working
Brightness, adapter, cables, inverter
Remove peripherals; check that F1 is not stuck down; press F2 with and without Fn; restart; on the DVI model check that the correct adapter is fitted; check the inverter and LVDS cable connections and the cables for damage; replace the inverter board, then the display assembly, then the logic board[1][3]
Stripes or spots that change when the lid moves
LVDS cable
didius traced this on a DVI model to the LVDS cable; Apple's procedure for a damaged display cable is a new display module[8][3]
Connect the device while the computer is asleep or off[1]
Lid will not latch
Display hook or top case latch
The hook in the display is pulled down magnetically and should retract when the button is pressed; a faulty hook means a display assembly, a faulty latch or button a top case[1][3]
Hold the latch towards the PC Card button and ease the battery out with a plastic tool; if the latch does not move smoothly, Apple replaces the rib chassis assembly[3]
Date and time keep resetting
Stuck reset button; backup battery; PMU card or logic board
Check the reset button is not stuck; do the backup battery test; leave the machine on the adapter with the main battery out for at least five hours; then replace the backup battery, and after that the PMU card (first model) or logic board (DVI)[3][1]
No sound from the speakers
Settings, cables, speaker wiring
Reset PRAM; check the speaker cables at the logic board. If headphones work, Apple replaces the heat exchanger, which carries the speaker wires; then the top case and logic board.[1] Use the headphone jack on the side when testing: ScutBoy spent time testing the line-in jack at the back by mistake[9]
No sound and the Sound control panel shows an external device
Headphone jack sensing
Plug headphones in and out, restart, reset PRAM; then the logic board[3]
↑ 2.02.12.22.32.4Apple Computer, PowerBook G4 (1GHz/867MHz) Service Source, hosted here as File:PowerBook G4 (1GHz-867MHz) Service Source.pdf. Symptom charts, PDF pp. 113-115: will not power on, memory errors, flashing question mark, no chime or video, shut-downs; 65 W adapter 661-1798.
↑ 3.003.013.023.033.043.053.063.073.083.093.10Apple Computer, PowerBook G4 Service Source (400 and 500 MHz), hosted here as File:PowerBook G4 (Titanium) Service Source.pdf. Troubleshooting articles of July-August 2001, PDF pp. 97-130: battery will not eject, latch not working, date and time resets (p. 121), error beeps (p. 127), no display or dim display; LVDS cable warnings pp. 70, 80, 82.
↑ 4.04.168kMLA forum thread "A tale of 3 Tibooks...", Mighty Jabba, October 2019. A non-working 500 MHz model showed signs of life after its PRAM battery was unplugged but still booted unreliably from its own drive. Community repair report.
↑ 8.08.168kMLA forum thread "TiBook with a screen problem", didius, Patnukem and Da Penguin, April-May 2008. Stripes on a DVI model's screen with the slightest cable movement; cables twisted during a hinge rebuild. Community repair report.
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