FixVideoResolutionHowto

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||<tablestyle="float:right; font-size: 0.9em; width:40%; background:#F1F1ED; margin: 0 0 1em 1em;" style="padding:0.5em;">'''Contents'''[[BR]][[TableOfContents]]||

== 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, mine is shown below.

''NOTE:'' Don't __change__ anything that
is written in the file for now. Just add the two lines. The snippet from my file
is just an example and may not apply to your hardware.
{{{
Section "Monitor"
     Identifier "FLATRON 995F"
     Option "DPMS"
     HorizSync 30-96
     VertRefresh 50-160
EndSection
}}}
Now save the file, close all open applications, and press {{{CTRL-ALT-Backspace}}}
to restart X. Assuming all goes well, you will be prompted to log into your
session again.

''NOTE:'' - If you are using XFree86 then you needed to edit {{{/etc/X11/XF86Config-4}}}.
Also if you have an issue where only 800x600 is available in the dropdown for screen resolution, then modifying the ''Modes'' line within the section in that file called {{{Section "Monitor"}}} and adding the required resolution could solve this.
{{{
        SubSection "Display"
                Depth 24
                Modes "1024x768" "800x600" "640x480"
        EndSubSection
}}}

== Resolution is not delivered by the vBios ==
This problem appears sometimes for laptops with "non-standard"-screen resolution in combination with certain Intel graphic-chips.
Background: It seems that the Video Bios (vBios) has to deliver the right resolution for the lcd-screen to enable the autoconfiguration to set this resolution. However sometimes the right resolution is not delivered and consequently the right resolution can not be implemented. You can fix the problem by overwriting the vBios setting in the RAM by using a program called 855resolution.

Here is the description of the 855resolution developer:
"855resolution is a software to change the resolution of an available vbios mode for the 855 / 865 / 915 Intel graphic chipset"
To install 855-resolution on Ubuntu 5.10 make sure that you have included the "universe" repository and type:
{{{
sudo apt-get install 855resolution
}}}
Once the program is installed you can use the program to list all available vBios modes:
{{{
sudo 855resolution -l
}}}
The result should look similar to:
{{{
855resolution version 0.4, by Alain Poirier

Chipset: Unknown (id=0x25908086)
VBIOS type: 2
VBIOS Version: 3412

Mode 30 : 640x480, 8 bits/pixel
Mode 32 : 800x600, 8 bits/pixel
Mode 34 : 1024x768, 8 bits/pixel
Mode 38 : 1280x1024, 8 bits/pixel
Mode 3a : 1600x1200, 8 bits/pixel
Mode 3c : 1400x1050, 8 bits/pixel
Mode 41 : 640x480, 16 bits/pixel
Mode 43 : 800x600, 16 bits/pixel
Mode 45 : 1024x768, 16 bits/pixel
Mode 49 : 1280x1024, 16 bits/pixel
Mode 4b : 1600x1200, 16 bits/pixel
Mode 4d : 1400x1050, 16 bits/pixel
Mode 50 : 640x480, 32 bits/pixel
Mode 52 : 800x600, 32 bits/pixel
Mode 54 : 1024x768, 32 bits/pixel
Mode 58 : 1280x1024, 32 bits/pixel
Mode 5a : 1600x1200, 32 bits/pixel
Mode 5c : 1400x1050, 32 bits/pixel
}}}
If the resolution of your sceen is not present then you can permanently overwrite a unused mode by the value of you screen. For example if you want to overwrite the mode 41 by the resolution 2400x1600 edit the file {{{/etc/default/855resolution}}}
{{{
sudo gedit /etc/default/855resolution
}}}
Your file should look similar to:
{{{}
#
# 855resolution default
#
# find free modes by /usr/sbin/855resolution -l
# and set it to MODE
#
MODE=41
#
# and set resolutions for the mode.
XRESO=2400
YRESO=1600
}}}
This will ensure that the vBios mode 41 is overwritten in the RAM at boot-time, before initializing the X-windows. Since the resolution is now available in the vBios your system should automatically be able to set the right resolution after rebooting.

== Incorrect DefaultDepth ==
Sometimes the automatic X configuration sets the colour depth to a value
higher than some hardware can properly handle. To see if this is the case for
you, first backup your {{{/etc/X11/xorg.conf}}} file.
{{{
sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.backup
}}}
Now open the file in your favourite text editor. I'll assume you'll use {{{nano}}}
for now since it is relatively simple to use, but you can use whatever text
editor you like.
{{{
sudo nano /etc/X11/xorg.conf
}}}
Search for the word {{{DefaultDepth}}} (notice it is one word) in that file.
The default colour depth set by Hoary is typically "24", but as mentioned,
some hardware may not be able to use a value that high. It's pretty safe to
change it to something like "16" just to test whether it solves your video
problems or not. If this change does not solve anything, it is just as simple
to change it back the way it was.

Once the value of {{{DefaultDepth}}} is changed, save the file, close all open
windows on your desktop, and press {{{CTRL-ALT-Backspace}}} to restart X. Assuming
all goes well, you will be prompted to log into GNOME again, hopefully at a
higher resolution.

== ATI - Refresh Rate & Resolution QuickFix ==

For those of you who run an ATI card with the fglrx driver, try running (in a Terminal):
{{{
sudo aticonfig
}}}

Follow the on-screen Instructions. This should fix the issue after restarting GDM.
For Instance on a Setup with:

 * 1 CRT Monitor
 * No TV-Out

I would be running these commands:

{{{
sudo aticonfig --initial --input=/etc/X11/xorg.conf
sudo aticonfig --resolution=1600x1200,1280x1024,1024x768
sudo aticonfig --force-monitor=crt1,notv
}}}

After you ran your aticonfig commands, you need to restart GDM, to restart GDM use
the following command:
{{{
/etc/init.d/gdm restart
}}}

That should fix it for good! If you experience a different Resolution being used for
GDM than your Desktop, you can scroll to the bottom of this Page to:
"GDM uses a different Resolution than my Desktop" to fix the issue.

== GDM looks right, but Gnome looks wrong ==
This problem occured on a vanilla installation of 5.10 that -- somewhat unnaturally -- was running under {{{VirtualPC}}}. Because this was not a normal device, I set the device to {{{VESA}}} and the resolution to {{{1024x768}}} in the configuration manager by:
{{{
sudo dpkg-reconfigure xserver-xorg
}}}
Naturally, make sure you configure these settings properly for your hardware.

These settings allowed GDM to present a normal login screen. However, completing login caused the display to fail.

Fix this by running the gconf-editor tool as a normal user and altering the screen settings within Gnome's XML configuration registry to equal the {{{/etc/X11/xorg.conf}}} settings:
{{{
startx gconf-editor
}}}
Browse the editor to {{{/desktop/gnome/screen/default/%d}}} where {{{%d}}} will probably be {{{0}}}. Select this node and change the {{{resolution}}} to your resolution of choice, and make sure {{{rate}}} is something functional for your display device as well.

Exit the editor, and try logging in through GDM again.

== GDM uses a different Resolution than my Desktop ==
This problem is easily solvable; to fix it do the following:

1) Make a Backup of your xorg.conf
{{{
sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.bak
}}}

2) Open xorg.conf
{{{
sudo gedit /etc/X11/xorg.conf
}}}

3) Locate your Screen Entry
{{{
Section "Screen"
}}}

You will find multiple entries similar to:
{{{
 SubSection "Display"
  Depth 24
  Modes "1280x1024" "1024x768"
 EndSubSection
}}}

The First Entry in the "Modes" Line is what GDM will use, so change it to something lower/higher
(Please make sure you know that your monitor and Graphic Card BOTH support this Resolution).

Save the file and close all running applications, restart GDM (/etc/init.d/gdm restart) and look if everything went fine.

If not you can always use:
{{{
sudo cp /etc/X11/xorg.conf.bak /etc/X11/xorg.conf
}}}

to restore your system to the previous state.

== The End ==
So far, this is all of the possible solutions I've collected for this problem.
If none of the above corrected your situation, consider posting your question
in the [http://www.ubuntuforums.org Ubuntu Support Forum] or in the #ubuntu
IRC support channel on the {{{irc.freenode.net}}} network.

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FixVideoResolutionHowto (last edited 2008-08-06 16:41:41 by localhost)