[NBLUG/talk] Display Resolution in Ubuntu Desktop

[Andrew]

Eric Eisenhart wrote on Tue, 3 Apr 2007 09:31:54 -0700:

> I suggest trying out editing xorg.conf and changing that
> monitor section to look more like:
> Section "Monitor"
>         Identifier      "DELL 1800FP"
>         Option          "DPMS"
>         HorizSync       30.0 - 80.0
>         VertRefresh     56.0 - 85.0
> EndSection

To effect this change, I would recommend you use the
dpkg-reconfigure tool, like this:

(For this procedure, you should probably plug your monitor
directly into your Ubuntu box. Autodetection will work best this
way. You can safely move the monitor from the KVM to the Ubuntu
box and back again without shutting the power off. It should be
fine to leave the keyboard and mouse connected through the KVM.)

1. Log out of your graphical environment.

2. Switch to a text console with Control-Alt-F1 and log in as
the system administrator.

3. Stop GDM (Ubuntu) or KDM (Kubuntu) with this:
sudo invoke-rc.d gdm stop
or
sudo invoke-rc.d kdm stop

4. Reconfigure the X server with:
sudo dpkg-reconfigure xserver-xorg

You'll first be asked if you want to autodetect the video
hardware. You should probably say Yes. Then you can just hit
Enter through many of the remaining questions. Of course, it
doesn't hurt to read the information on the screens - you may
want to make the occasional change. And you'll probably learn
something, too.

When you get to the point where it asks to autodetect the
monitor, say Yes. You'll then be given a chance to select which
resolutions you want to use. Some will be pre-selected. Select
the ones you want and deselect the ones you don't. Use the up
and down arrows to see the whole list. After that, you'll be
given a choice of Simple, Medium, or Advanced monitor
configuration. Choose Advanced and fill in the horizontal sync
and vertical refresh rates that Eric gave you (they may already
be filled in). If you have your monitor's documentation, double
check those numbers.

Hit Enter a few more times to finish the configuration and
you'll be informed that a backup has been made of your original
xorg.config file (just in case) and a new xorg.config file has
been written.

5. Restart Ubuntu from the command line
or
Restart GDM or KDM as in Step 3 above, but using the start
parameter instead of stop. You'll probably be switched over to
the graphical login screen automatically, but if not, hit
Control-Alt-F7. Then restart Ubuntu.

6. While that's happening, move your monitor back to the KVM
switch and switch the KVM over to another system. Once Ubuntu is
back up, check if your problem is fixed.

Some of these steps and more info can be found here:
https://help.ubuntu.com/community/DebuggingXAutoconfiguration
http://doc.gwos.org/index.php/ChangeResolution

Hope this helps,

A.