One way to fix a Mac that won&#039;t login

So the other night, while covering Sundance Film Festival for Blogging Sundance and Cinematical, we had a problem with Jason Calacanis's Powerbook G4. It would boot and run through the loading Mac OS X screen very quickly, but at the point where it was supposed to load the login screen, we were greeted by the default blue OS X background and the mouse pointer arrow and nothing else. And it just stayed there.

We tried rebooting, we tried zapping the PRAM, and we both booted into single user mode and booted the computer in target disk mode, attached to my laptop, and performed a disk check on the computer. No problems with the disk. The machine just wasn't booting.

After throwing up my hands and proclaiming there to be some odd hardware failure, it suddenly hit me: maybe the login window preferences were borked. We booted into single user mode again (reboot and hold down the command s button). I ran all the commands that you have to run in order to write to the disk (

/sbin/fsck
-y

followed by /sbin/mount -wu /). Then I ran:

cd Library
cd Preferences
mv com.apple.loginwindow.plist BACKUPcomappleloginwindowplist

This makes a backup copy of the preference file associated with the login window and erases the original file in the process. After I was done, I typed reboot at the prompt and hit the return key. OS X rebooted and was forced to create a new preference file for the login window, thus fixing the problem. Huzzah!

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So the other night, while covering Sundance Film Festival for Blogging Sundance and Cinematical, we had a problem with Jason Calacanis's...

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georg

thank you for this article. you are my hero of the day. whithout your hint, i would have re-instaled os x. ;-)

February 17 2006 at 4:29 AM Report abuse Permalink rate up rate down Reply

Carbunkle

I agree with Michael. Applejack should be installed on every new computer by default. It works.

January 26 2006 at 11:29 AM Report abuse Permalink rate up rate down Reply

topher

by any chance... do you have a dual monitor setup?

January 26 2006 at 3:45 AM Report abuse Permalink rate up rate down Reply

Michael G

http://applejack.sourceforge.net/
AppleJack does it magic in single user mode.
It combines several troubleshooting things that you can access in single user mode by hitting a few keys instead of typing endlessly[...]
It is meant as "get back on your feet" - not general maintenance - if your mac can not start up normally.
I have it on my mac as a first line of defense.

January 26 2006 at 3:23 AM Report abuse Permalink rate up rate down Reply

Esquare

So, what you did was item #5:
http://docs.info.apple.com/article.html?artnum=106464

January 26 2006 at 3:18 AM Report abuse Permalink rate up rate down Reply

Pip

Once, back in the 10.1 or Jag eras, my iBook made it to the login screen, but wouldn't log in. I went in in single-user, and deleted /Library/Caches, and it worked

January 26 2006 at 2:21 AM Report abuse Permalink rate up rate down Reply

Brandon

Speaking of tips, where do i submit mine?

January 26 2006 at 1:50 AM Report abuse Permalink rate up rate down Reply

Dan Bedford

Quote #2:

"You know, if you just hold the shift button down until your desktop comes up, and then restart normally, it will accomplish the same thing.

Safe mode will check your hard drive and remove said preference file for you, among other things."

Posted at 11:36PM on Jan 25th 2006 by Adam Fukushima
-----------------------------------------------------

Safe boot does not do this for you. Here is the Apple document describing just what it does:

http://docs.info.apple.com/article.html?artnum=107392

As for this troubleshooting tip, this is a great one! I wish Apple Tech Training would get more detailed with command line troubleshooting tips. Maybe next time I need to certify, they will have added more of this stuff...

January 26 2006 at 1:27 AM Report abuse Permalink rate up rate down Reply

edan

I've got an iBook G3 800 that simply will not boot. It started exhibiting these odd shut downs from running in OSX. The machine would operate normally for 8-20 minutes w/o issue and would simply shut down. At this point it simply will not boot, on AC power, battery, after reseting the PRAM, target disk mode, and every other possible trick you can imagine. The machine has been gone over end to end and for the life of me I cannot figure out why it kept shitting down or why it will not boot at all now.

Any ideas? I've hit the support.apple forums, other apple support site and even taken the book into the apple store. The geniuses tell me it's out of warranty, apple care and all and that it'll cost at least $100 to diagnose. At this point I'm thinking, wait for the new Intel MacBooks, but this machine used to work great....

January 26 2006 at 1:23 AM Report abuse Permalink rate up rate down Reply

Scott Hughes

This seems to be a somewhat common problem. I had a discussion about this with a few others here:

http://blog.globalreset.org/articles/2005/11/04/mini-crash

I'd like for someone to explain what the problem is exactly. As in, what is causing the .plist to become 'borked'?

January 26 2006 at 1:10 AM Report abuse Permalink rate up rate down Reply