Ubuntu support question: massive GUI failure. Reboot is not helping.

PM Ryan or Markyy.

If you have manually edited the file /etc/X11/xorg.conf, you can try to delete that file and start X again (using the startx command). X will attempt to rebuild the file according to autoconfiguration data if the file is not present.

If you haven’t manually edited that file, then please disregard the above. However it will be useful to know a few things:
1) what specific changes did you make, and how did you make them?
2) what sort of TV are you using, and what kind of connection (DVI, HDMI, RCA cable, etc)?
3) did the system prompt you to reboot?

Usually you don’t need to reboot to get things like this done. If the system asked you to reboot, that is significant information, especially if you can remember the message it gave you.

@koanhead I went into the Nvidia X Server panel and scrolled around until I found the X Server Display Configuration.
I am using an old CRT television. The computer is connected to it with a yellow RCA cable, which is plugged into an s-video/RCA adapter. I think that the reboot was my idea.

X and the nVidia driver know about screens attached to the computer via a mechanism called EDID. Your old TV probably does not support EDID, and even if it does, EDID won’t work over your RCA cable. Therefore, the system has no way of knowing that the TV is there unless you have specified it in some way. I also have the nVidia driver and its control panel installed, and I don’t see any obvious way to set this up that way. Can you be more specific as to which options or menus or whatever you used in nVidia Control Center?

If you have only one video card (nVidia) and the RCA plug is attached to that card, then you might be able to sort of use the TV without making any changes, if you are ok with trying to use the TV as a crappy, low-resolution mirror of your main desktop space. In order to get TwinView to work you will need to hack X- and without EDID this will mean editing the /etc/X11/xorg.conf file by hand. I can help you with this if necessary.

I’m thinking that your first step, though, is just to zap the existing xorg.conf. This should work to get graphics up and running

Just log in to the command line and enter this command:

sudo mv /etc/X11/xorg.conf /etc/X11/old-xorg

You’ll be prompted for a password: enter the password you use to log in.

This will “move” the file’s contents from the old path to the new path. It doesn’t matter too much what you call the new file, but keep it in the same directory so that you can find it later. It’s best to keep these backups around for a little while at least, they can be very useful for troubleshooting.

After you have done this, with the RCA cable plugged in and the TV on and tuned properly, reboot the machine:

sudo reboot

When the machine reboots and X starts, it will try to read the xorg.conf file. If the file isn’t there, it will attempt to rebuild the file with available autoconfiguration data.

If this works and restores your graphical desktop, it might be instructive to diff the new file against the old one to see what changed… but if your graphics are working again you might not care ;^)

@jerve is another good computer tech around here. I would help but I’m a windows guy.

IF you’re using Ubuntu, he won’t have a static xorg.conf – it’s deprecated from !0.04 onwards, and is generated on the fly.

Incidentally, any changes you make to the nVidia control panel shouldn’t be permanent unless you launched it through the terminal with sudo.

I think you should attempt to reconfigure your x-server by entering this into the terminal:

@@sudo dpkg-reconfigure -phigh xserver-xorg@@

I’d be inclined to do this with the TV disconnected.

I’ve heard of some pretty crazy things with monitors in my time, but never a complete GUI failure from connecting a TV to the S-Video output. Are you sure your GPU isn’t faulty?

@the100thmonkey is quite correct, that command

sudo dpkg-reconfigure -phigh xserver-xorg

should be run before any of the steps that I mentioned.

I’m running 10.04 on my primary computer, and it has a detailed (autogenerated) xorg.conf which was last modified about four months ago, which is about the time I swapped out video cards. I didn’t zap the xorg.conf at that time, as the system came up without incident and used the new card without fuss (went from nvidia to nvidia).

I’m not sure what you mean by a “static xorg.conf”. Do you think my advice to mv xorg.conf and restart X is bad/wrong or will break things? Please advise.

@koanhead – No, I think it’s the right thing to do, and didn’t intend to disagree with anyone – as I understand it, the team behind xorg has been trying to move away from a conf file that is generated and stays that way – static – for some time without the intervention of either the user or programs that write to it, and move towards on-the-fly generation of the file.
I based my response on this thread on the Ubuntu forums, although I notice that it’s now getting on for 3 years old and goals may well have changed. It fits with the work on the free nVidia 3D open GL driver that is underway, though, and Ubuntu’s philosophy – it should just work, and the user shouldn’t have to go digging around conf files to get things to work.

Personally, I suspect a hardware problem, although I will be very happy if I’m wrong.