Revision 19 as of 2006-07-25 01:13:38

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Introduction

This Howto is intended for those who have installed or upgraded to Hoary, and their screen resolution is very low. A possible reason for this is that your hardware (video adapter/monitor) may not have been detected properly. There are several fixes that I have seen in the forum and in the IRC support channel. One solution will work for one person and another solution will work for someone else. I hope to provide several different solutions here, ranked in decending order from what I have seen to be the most popular and successful solution to those solutions that have helped only a few. This way, hopefully it will provide an answer for everyone. Let's start with the most popular fix.

For ATI Users I recommend reading the ATI - Refresh Rate & Resolution Quickfix part on the bottom of this Page.

Run the Autodetect Script Again

I'm not sure that this is the solution that works for the most people actually, but it most certainly is the quickest and easiest one. All we're doing is running the same script that tried to detect your video hardware when you initially installed. Sometimes this does help. Run the following command.

For Ubuntu 6.06 (Dapper Drake):

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.custom
sudo sh -c 'md5sum /etc/X11/xorg.conf > /var/lib/x11/xorg.conf.md5sum'
sudo dpkg-reconfigure xserver-xorg

For Ubuntu 5.10 (Breezy Badger) and earlier:

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.custom
sudo sh -c 'md5sum /etc/X11/xorg.conf > /var/lib/xfree86/xorg.conf.md5sum'
sudo dpkg-reconfigure xserver-xorg

After completion, close any open windows or programs you have running on your desktop and press CTRL-ALT-Backspace to restart X. You will be asked to log into your GNOME session again and hopefully everything will be fixed. If not, try the next solution.

Undetected Monitor Specs

Open the file /etc/X11/xorg.conf in your favorite text editor. I'll assume you are using nano for an editor as it is fairly straight forward.

sudo nano /etc/X11/xorg.conf

Now look for a section in that file called Section "Monitor". Once you find this section, look at the lines of text between Section "Monitor" and EndSection. There should be two lines in there that begin with the words HorizSync and VertRefresh. If those lines don't appear there, don't worry. There is a good chance that we've found the problem already!

You will need to gather two bits of information for your monitor now, either from your User's Manual, the command line, or from online. We need the horizontal sync frequency (usually measured in kHz) and the vertical refresh rate (usually in Hz). Finding these values usually just involves searching [http://www.google.com Google] with the model of your monitor. Both of these values are typically given in a range such as "30-98 kHZ" or "50-160 Hz". Write those values down, or otherwise keep them handy. Additionally, if your monitor supports it, you can just run the following command:

sudo ddcprobe | grep monitorrange

The first two values returned are your HorizSync rates, the second pair is your VertRefresh values.

There are two ways to enter your monitor information into the file. One way is to run the following commands which will regenerate the file and ask you for the values in the process.

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.custom
sudo sh -c 'md5sum /etc/X11/xorg.conf > /var/lib/xfree86/xorg.conf.md5sum'
sudo dpkg-reconfigure -plow xserver-xorg

The second way is to simply add those values to our /etc/X11/xorg.conf file with a text editor. But first, lets make a backup of that file just in case an error is made.

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.backup

Editing this file so that it works involves adding two extra lines to the Section "Monitor" section of that file. For example, min