Blue Screen (of death?) and Authorization Problem

Dear fellow Mactonians .

I’m having a problem – big problem.

Every time I try to start my powermac G5 (2005) I get past the gray loading screen with the apple, but after this I’m stuck with a blue screen and the mouse pointer in the left top corner.

I’ve looked this up on the Internet and found different solutions but none of them worked.

This I’ve done so far:

1) I started in safe boot (holding shift) but that only takes my to Darwin/BSD logon screen. It asks for at username, but I can’t type in the following password.

2) I tried single-user-mode. I did “fsck” and it told me “everything appears to be ok”. Also tried: mount -uw / etc and that didn’t do it either.

3) Tried to boot from MacOS CD installer. Ran utility program. Repair disk and repair permissions. Still blue screen after reboot.

4) I did the “option+command+r+p” – nothing.

5) Opened the computer and reset the PMU button manually. Still blue.

6) Changed the PMU-battery. Still the same – and now – really annoying blue.

7) I can’t do an “archive and restore” – not enough space on the computer.

8) In single-user-mode I ran: tail -20 /var/system etc… and I suspect here’s a bit of a clue:

Some said:

Loginwindow(80): Login Window Started Security Agent

Loginwindow(80): AuthorizationRef doesn’t have a username.

Is this my problem?

And for some now obviously stupid reason I don’t have any backup of all the data, music, files and so on.

Therefore I can’t do anything that will delete the HD.

So please help me if you have any idea what to do – my life is on that precious Powermac…