Booting: Cannot get to login screen

[ascomycota]

When I turned my iMac on this morning (iMac G5 PPC 10.5.8) it went through all of the "normal" steps (gong, grey screen, apple logo, progress wheel, blue screen) and stopped at the blue screen. Thinking it was just a fluke, I shut the machine down and restarted, only to have it stop at the blue screen again.

After disconnecting everything going into the iMac except the keyboard and mouse, I attempted to boot into safe mode but it stopped at the blue screen again. I tried single user mode too but I didn't get any further than the blue screen.

Next, I flashed the PRAM (big gong, single quieter gong) and afterwards it came to the blue screen.

I reattached my external drive and selected to boot from a 2-day old backup. Using the backup I was able to log into both my regular account and my "test" account (without login items).

I still cannot login (except to my external drive backup). Any ideas?

 

[calderone]

Disconnect the external. Boot the machine, immediately hold command + v. This will put you in verbose mode, watch for anything odd, namely where it stops. It might just go to the blue screen.

If you can't figure out anything from there, try some things here: http://support.apple.com/kb/TS1411

Especially #5

If your computer still starts up to a blue screen, follow these steps.
Start up the computer in Single-User Mode.
Type: mount -uw /
Press Return.
Type: 
mv /Library/Preferences/com.apple.loginwindow.plist preferences2.old

Tip: There is a space between ".plist" and "preferences".
 
Press Return.
Type: 
mv /Library/Preferences/com.apple.windowserver.plist preferences3.old
 
Press Return.
Type: reboot
Press Return.

 

[iLog.Genius]

I would try booting to Safe Mode first by holding down the left Shift key on boot up. By doing so, Safe Mode will recreate critical boot files that may have become corrupt which usually is shown with the blue screen. If that doesn't work, try the method above.

 

[calderone]

I would try booting to Safe Mode first by holding down the left Shift key on boot up. By doing so, Safe Mode will recreate critical boot files that may have become corrupt which usually is shown with the blue screen. If that doesn't work, try the method above.

This is true. Safe Boot deletes the local shared cache (/var/db/dyld/). Just a note, the actual recreation of the shared cache happens when you boot normally after having safe booted.

 

[ascomycota]

calderone and iLog.Genius,

Thanks for the help. I'll try the safe boot again tomorrow morning (I'm away today). If that doesn't work I can try single-user mode again as well.

If I am still unable to get past the blue "wall", is there a way I could do it via firewire and my MacBook?