10.4 security update issue

[almaink]

Halftone you may need to re-set you open firmware. A PRAM reset isn't quite the same thing. Try Joe's motherboard reset idea, and if that doesn't work post back.

[mc hristel]

We had this happen to us about 6 months ago.  Try starting the computer holding down the shift key.  That should get you into safe mode. 
If it boots up, log into the Administrator account and use disk utility to repair permissions and delete these files:

admin/lib/preferences/ com.apple.systempreferences.plist
admin/lib/preferences/ com.apple.sysenuiserver.plist
admin/lib/preferences/ com.apple.finder.plist
admin/lib/preferences/ com.apple.universalaccess.plist

Then reboot normally.  The computer should boot up just fine, and the files you deleted will be recreated since they are just preferences.

Good luck
-MC

[frailer]

I know you're being bombarded with suggestions, bu-u-ut...you could also try a Zap PRAM, [resetting parameter RAM].
On startup, hold down Cmd+Opt+P+R keys. Wait, [in theory], until you get 3 chimes. Let go of the keys and wait for it to restart normally. [You hope... :rolleyes:]. Sounds like you won't get this far, but, ya never know...

Battery replacement would be an early elimination, though, as Joe says.

[Halftone]

Thanks again for all the responses. New things I tried and didn't work:

1) I tried resetting the mother board
2) Replaced the battery
3) Tried booting in safe mode

I'm starting to think it's a bad board.

Thanks for all the help.

[Joe]

It is starting to sound like it. Bummer.

[Halftone]

Well the boss brought in his computer from home which is the same model. I swapped the hard drives and of course the bad machine didn't boot but the good one did. So at least we can do a new backup of his computer before we bring it into the shop. Definitely seeming to be a bad board.