Ubuntu 10.04 freezing and Ctrl + Alt + Backspace does nothing but music keeps playing

I'm having intermittent problems where the screen will freeze in Ubuntu. I've tried using Ctrl + Alt + Backspace to restart the X-server, though this does nothing. When the freeze occurs, there's a small square of black dashes around the mouse pointer - maybe 1 inch in size. These dashes look a lot like a 2d barcode. The rest of the screen looks normal, but I can't move the mouse and none of the keyboard shortcuts work to do anything. However, music that I begin playing before the freeze continues to play, which seems to indicate it hasn't stalled up completely.

I've noticed a similar freezing problem when I'm using Windows 7. That is, I see the same barcode like dashes around the mouse pointer when it freezes up. So I'm guessing it's either a driver or hardware problem. I thought if it was a hardware problem though, the whole computer might stop working (i.e. music would stop playing)? The video card I am using is an Nvidia, and I believe it's in the 7600 range. In Ubuntu I have the drivers for the card set to the latest available (proprietary). Ideally I'd like to be able to continue using the proprietary drivers. Is there any known issues with the drivers for this model graphics card, or has anyone experienced the same problem and knows how to fix it?

Bryce Thomas

Posted 2010-05-26T10:03:12.787

Reputation: 671

Answers

It's your VGA I'm pretty sure. Ctrl+alt+backspace is disabled on the newer Xorg servers (oh revolution hell yeah), but you can enable it. I used to edit the xorg.conf for this but it seems Ubuntu provides an easy way. Try this one:
http://lifehacker.com/5385615/restore-ctrl+alt+backspace-behavior-in-ubuntu-910

About the fix: Replace your vga. About 10-15$ you can get a used 9300/7600/8400 NVidia, all of them supported by the latest drivers if I remember clearly. (Try using your PC with a different VGA and see if the problem keep occuring. Anyway, you won't be able to restart your Xorg like this since the whole PC freezes up. (No the magic combination is the same.))

Apache

Posted 2010-05-26T10:03:12.787

Reputation: 14 755

It's beginning to look like I might have to try this. – Bryce Thomas – 2010-05-26T16:36:09.960

You won't be able to use this I guess. You should get a new vga or use the warranty.. something. If the GPU dies/does the freeze, no way you can get out of that. – Apache – 2010-05-26T19:04:16.917

Additional info: to restart the X-server you could go to a virtual console with ctrl + alt + f2, login, and then use: sudo /etc/init.d/gdm restart

More about virtual consoles: Linux / UNIX: Virtual consoles

Likso

Posted 2010-05-26T10:03:12.787

Reputation: 65

Unfortunately I can't get to the virtual consoles when the freeze occurs :( – Bryce Thomas – 2010-05-26T16:35:27.873

Here you have to do this: sudo service gdm restart – Apache – 2010-05-26T19:03:40.503

then try do to this: Alt + SysRq + r that takes keyboard and mouse control from the X server. This is a Magic SysRq Key that permits to give commands directly to the kernel, and it's enabled by default on ubuntu. After typing that you could retry to hit ctrl + alt + f2 :) – Likso – 2010-05-27T08:14:03.117

@Shiki - I can't get to a console to do that unfortunately. @Likso - I'll give that a try next time it freezes up. – Bryce Thomas – 2010-05-28T14:09:28.613

It turns out that it was indeed my video card causing it to freeze up. After switching it with a replacement video card, I've had no problems in several weeks.

Bryce Thomas

Posted 2010-05-26T10:03:12.787

Reputation: 671

Don't hesitate to accept your own answer, if it contains the solution to your problem. – Gnoupi – 2010-08-14T12:31:54.947