Powerbook G4 black screen - logic board?

I think I may have a dead Powerbook G4, for some time I have been having intermittent hard freezes/kernel panics, often when choosing sleep, sometimes just randomly.

Now when I restart I have a black screen, I hear the chime and power is getting through as the adapter light works and caps lock key is illuminated, however there's no sound, the eject button doesn't eject and the system 10.5 DVD is in the drive.

I've done all the usual stuff and more; made sure the screen brightness is at 100%, reset the PMU, zapped pram, restarted in safe boot (worked once but never again) tried to restart with system DVD, swopped RAM modules around, tried a different battery, tried starting in single user and verbose mode. Some of this worked once at the beginning but I've been unable to get it to work again. I've probably restarted now around 30 times.

Memory is from crucial, I have tried removing each of the dimms in case one is faulty and restarting - no luck, I wonder if there's any chance it could be the pram battery, but my best guess is it's the logic board or the hard drive.

For what it's worth, today I managed to run diskwarrior via firewire target disk mode - it found around 20 errors and replaced the directory. While I was connected I tried to repair permissions using disk utility however I received some sort of error about 'no valid packages' and it was unable to run. Tried to start it up again, still no luck. I now have an appointment at the Mac store on Thursday...

Before I admit defeat and take it in for repair has anyone got any thoughts?

Thanks in advance

Jim

Hmm, it could be the board certainly or the drive as you said.
Have you tried a fresh install of the OS since running DW? The no valid packages error is a little odd.That usually means the the base system pkg is missing from the library, something the DW did I suspect.

Thanks for the reply I wondered whether Diskwarrior might have caused the missing basesystem pkg also. I've just done an archive install over firewire (seems to have worked) and I'm backing up the drive using superduper. I'll restart shortly, however I'm pretty sure that the hard drive was OK and this won't have made any difference...

"Computer says no"

Hard drive is OK and it's backed up now but still no start-up - same symptoms.

Does Diskwarrior have a hardware test built in? Or do you have an Apple Hardware test disc?
If so have you run them? They would normally highlight video card/logic board issues.

I'll see if I can locate Techtool pro tomorrow to see if I can isolate the fault further.