iBook G4 Problem Diagnosis

[J English Smith]

Hey, all - one of my G4 iBooks is showing its age. Wondered if this is indicative of a logic board failure - can anyone help me confirm?

1. Startup chime occurs

2. Screen does not light and no further boot

3. Last boot prior to above, booted into open firmware, then after mac-boot, started normal boot and got the greyed out "You must restart your computer" screen

4. I have used TDM and checked the drive and using DiskWarrior have checked the drive - I get an OK on its SMART status and have used DW to rebuild the directory on the drive

5. I switched out the additional RAM chip in the machine last night, no change

6. I have tried a PRAM zap using the keyboard command, it does a double chime but then boot does not proceed.

7. All of the above hooked to power main not relying on battery power

Anything else to try? I doubt I'm wanting to do a complete teardown on her if it is the logic board. I've heard that's a rather intensive procedure.

Of course, all of my nearly worthless iBook 500s continue to chug right along - better components? Less heat?

 

[rsolberg]

Have you performed a PMU (power management unit) reset yet? Here's Apple's instructions: https://support.apple.com/en-ca/HT1431

 

[IlikeTech]

Which iBook is this?

 

[Nathan]

I think the normal chime is supposed to mean it passed at least a basic hardware test and is working. Is it possible the backlight is off or that it has failed (try the flashlight test)? I know on mine (iBook G4 14" 1.42) the lowest backlight setting (using keyboard brightness controls) is basically OFF. If you've got the miniVGA to VGA adapter it might be worth a try to see if you get external video.