Console/single-user No Video

J

jghaffner

Registered
Hi,

I am an experienced Mac user and administrator (since 1989). I am comfortable with the command line/terminal in OS X.

Setup:
PowerMac G4/400 (AGP Graphics) - Mac OS X 10.4.1 - 512MB RAM - Stock video card (ATI RagePro 128).

Problem:
When I try to reboot in single-user mode, I do not have any video. If I type 'exit' and return (blindly), the login window comes up, so I think it's actually giving me a command prompt, but not drawing to the screen properly.

If I type ">console" in the User Name field of the login window, I get a black screen with one line across the top:
6/24/2005 12:51 getty: /dev/console: Operation not supported by device.

If I reboot and zap the PRAM - I can get into single-user mode once.

I am not sure these symptoms are connected, but it seems that they are.

What I've Done:
Fixed permissions
Zapped PRAM - only temporarily fixes.
Reset the PMU.
Reseated video card.
Logged in as another user (admin level) - same symptoms.
Googled for error message.
Searched Apple's discussion boards.

These symptoms started after I upgraded to Tiger.

What else can I look at here? How can I get single-user mode back?

Best Regards,

John Haffner
 
Check if you have any software running that could interfere with the default output. This is not really my domain of knowledge, but it seems reasonable to believe a third-party program is changing settings it isn't supposed to change, since it works the first time after a PRAM reset.
 
Update:
I have discovered that if I change my resolution to 1024 x 768 before attempting single-user mode, I can see the text on the screen. My normal resolution is 1280 x 1024.

Not sure exactly how, but the video output has changed since upgrading to Tiger.
 
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