How do I get ubuntu to recognize my monitor's proper resolution again?

May 28, 2007 4:59 PM

During the Ubuntu install process (text-based), it asked what screen resolutions I would like X not to include. Not thinking, I selected my preferred resolution (1280x1024, the most my monitor can handle) and hit continue. Now I can't use that resolution in my finished install, as it's not on the list in the Screen Resolutions system panel. How do I recover that possibility? Thanks!
posted by invitapriore to computers & internet (12 comments total)

From the command line, type

sudo nano /etc/X11/xorg.conf

and look for the screen section (starting with the line that reads Section "Screen"). You'll want to add your resolution for every "Display" subsection below... the format should be self-explanatory.
posted by gsteff at 5:14 PM on May 28, 2007

Just in case... Control-O saves in nano, and Control-X exits. Feel free to use another editor if you don't like nano.
posted by gsteff at 5:15 PM on May 28, 2007

You can use the command "sudo dpkg-reconfigure xserver-xorg" and that will run through the list of monitor resolutions again or you can always edit the "/etc/X11/xorg.conf" by hand and add the resolution you want under the "Screen" section of the file.
posted by calumet43 at 5:17 PM on May 28, 2007

Arr. Tried edciting xorg.conf and restarted X, to no avail. In trying to go through the auto-configure routine again, it displays the list of resolutions, and there's no button I can actually press to include a new one (or even remove an already included one!). What do I have to do to change the selection?
posted by invitapriore at 5:28 PM on May 28, 2007

If you go throught the dpkg-reconfigure routine you will eventually see a list of screen resolutions. Use the up and down arrow keys or the tab key to move the cursor, and use the space bar to place an X on your selection. Then move to the OK button and hit Enter to go to the next screen.
posted by euphotic at 5:59 PM on May 28, 2007

I'm actually in the same boat, in that the list of available resolutions in my dialog box is not the same list in my conf file, even after editing, reconfiguring, and restarting.
posted by potch at 8:21 PM on May 28, 2007

I'm not 100% sure on this, but you might try renaming your current xorg.conf file to something else (xorg.conf.old or xorg.conf.backup both work) and then running "sudo dpkg-reconfigure xserver-xorg" .. this makes sure that dpkg-reconfigure runs without 'seeing' your existing xorg settings (since it will look for xorg.conf and not find it, because you renamed it). It should be like running it totally fresh.

If that doesn't work, then you'll just want to edit xorg.conf by hand, as a superuser, and insert your desired resolution into the list of possibilities. It's really not that hard to do, although the first time you edit a config file it can be intimidating. You'll see a section of the file where on one line it'll give a bit depth (e.g., "16" or "24") and then on the next line, various resolutions, also in quotes ("1280x960" "1024x768"). Add your resolution in on that line, save, and restart.
posted by Kadin2048 at 9:09 PM on May 28, 2007

This is a driver issue. What graphics card are you using?
posted by IronLizard at 9:31 PM on May 28, 2007

Oh wait, nevermind. Ignore me.
posted by IronLizard at 9:31 PM on May 28, 2007

This is a driver issue. What graphics card are you using?

Oh wait, nevermind. Ignore me.


No, you're right (unless I've missed something in one of the replies here).

The quickest and most pain-free solution here is to install the proprietary drivers for the graphics card, assuming that you're running an nVidia or ATI card. Ubutnu makes this easy nowadays. I think you've just got to select it using the notification area/system tray icon that handles proprietary drivers, at least on 7.04.

Once you've done that, add the entry to your x.org config file, as people have described (or just alter the one that's already there).

You probably won't be able to get 1280x1024 using the open source drivers without a lot of fiddling around, which might be beyond your skill level (right now!). The incorrect resolution is a notorious problem.

Once you have the resolution you want, and as your knowledge of Ubuntu/Linux improves, you can work on switching back to the open source drivers.
posted by humblepigeon at 1:23 AM on May 29, 2007

I think his particular problem is that he specifically told Xwindows to exclude that particular resolution (I missed that part, which is why I mentioned the driver issue). Getting the manufacturer's drivers certainly won't hurt, though. I could only do 800x600 until I downloaded ATI's drivers and alien'ed them. Now, I'm in 1600x1200.
posted by IronLizard at 2:30 AM on May 29, 2007

Hey everyone, thanks for all your suggestions. Reconfiguring X was the solution, I am just not sufficiently knowledgeable in command-line fu to know to press the space bar to change the value of a check box. (I must have tried every other key, too...)

Thanks again!
posted by invitapriore at 8:41 AM on May 29, 2007