Blue screen on launch - tried all solutions offered in discussions - no joy

Question

Hi
I started up my G5PPC running OSX 10.4 (not sure which version and you'll soon see why). It went to a the grey apple screen, whirs a bit and then gos to a blue screen. I was able to move my cursor. But that was it. Nothing else happened.
I read all the forums and as a result of their collective wisdom did the following. At each stage I rebooted the G5 and got the same result as above with very little variation unless noted below.
I disconnected all externals etc and powered off etc.
I ran Techtool - and all my bits are in working order.
I ran disk utility - repaired permissions and verified disks.
I ran disk warrior - it told me my boot drive had 11 overlapping files but it created a new directory and sorted those out. It looked like I was in business.
However, when I turned the G5 back on I got a 0S9 style graphic of a file and a flashing question mark which Alsoft says means you have to reinstall OSX.
I have a bootable back up of my boot drive so I thought there would be no harm trying that before doing a full restore.
After the first disc of my install discs went in, the G5 unexpectedly rebooted itself and stuck while the fans went crazy.
With my original boot drive now wiped but with no OSX installed, I decided to restore it from my back up via super duper.
Once that was done I tried to reboot - back to blue screen via the grey apple screen.
I tried to boot my G5 from the firewire external drive (which is bootable) which didn't work either.
Both before the restore and after, using my Macbook pro, I set the G5 up in target mode and had a look at my boot drive. It was nearly full for a start so I deleted a lot of unnecessary stuff off it (eg old video rushes - no programme files). There's 50gig free now.
Everything seems to be in tact however and as noted above, none of the software checks (Diskwarrior, Disk Utility, Tech tools) are reporting any problems with the hard drive - like bad sectors or whatever and it has a new clean directory courtesy of DiskWarrior).
Any suggestions about next step?
someone on here got there machine up and running by deleting a the startupservices plist which I did via my mac book pro accessing my G5 via target mode. It worked for them but in my case merely caused the G5 to create a new plist. It still went to blue screen (though I briefly saw a small window which looked like a user default log on window).
I ran disk warrior again. No problems found.

Answer 1

Here is something worth ponder and consideration that not everyone takes to heart:
When a disk utility repair fixes major over lapping extents, figure you are lucky to be able to Preview your drive and back it up.
But then you really should / need to / strong recommendation - REFORMAT.
And then keep your system cloned (emergency, working backup, and always test new updates, patches, releases on a test backup).
Disk Warrior doesn't test files and content fully, it doesn't look for weak spots or marginal bad sectors. And it doesn't know if file is garbage or good, just that the directory points to file.
SuperDuper optimizes directories, skips temp files and logs and things best built on first time boot (and one reason to always do a Safe Boot after cloning or updating).
Disk Warrior, if you option + click on the REBUILD directory button it takes you to a 2nd screen to "scavenge" more thoroughly, which is what I use.
When HFS+ gets low, trouble is the directory can become corrupt in ways that it loses files, data, and pointers to files.
You did a very good job, and more than many or most, it seems there are weaknesses in HFS+ and in tools to find and repair problmems. And getting low on disk space... well, why isn't there a quota system.