can't detect external LCD display and gnome-display-properties window lies in external monitor

Bug #566862 reported by Santiago Roland on 2010-04-19
This bug affects 1 person
Affects Status Importance Assigned to Milestone
xorg-server (Ubuntu)

Bug Description

Binary package hint: gnome-control-center

In my HP6735s notebook i plug my RCA 32" LCD TV with VGA-VGA plug. This TV is 1280x800 px widescreen the same resolution as my notebook. After plugging it, when executing Minotors application (gnome-display-properties) and hit autodetect, this is what happens. The detection make the display blank for a second... and the display comes back but the 32" LCD TV shows nothing (Blue screen like waiting for signal) and the gnome-display-properties is gone!!!! i think that it crashed... but i discover that the gnome-display-properties window lies in the other monitor. I figured this out by taking a screenshot in which both monitors can be seen and the gnome-display-properties has moved to the other monitor that i can not see because it has wrong resolution, this resolution is 1280x1024 and the LCD monitor not support this. The only way to use the external monitor is to do this.
1) with ALT key pressed try to catch the window (you are blind at this point) and drag gnome-display-properties window to the notebook monitor
2) Set the > Show the same image in both monitors and it would set resolution to 1024x768... this is wrong for aspect ratio of notebook monitor and LCD TV but is the only way to see a movie with it.

Back in Karmic 9.10 i used ATI propietary binary driver and the TV was detected succesfully at 1280x800 and cloned image as well. This behavior should be reached by gnome-display-properties.

see the screenshot, note that the right panel you can NOT see because the resolution is wrong. and dragging the window is very difficult.


ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: gnome-control-center 1:2.30.0-0ubuntu4
ProcVersionSignature: Ubuntu 2.6.32-21.32-generic
Uname: Linux 2.6.32-21-generic x86_64
NonfreeKernelModules: wl
Architecture: amd64
Date: Mon Apr 19 15:59:24 2010
ExecutablePath: /usr/bin/gnome-display-properties
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta amd64 (20100318)
SourcePackage: gnome-control-center

Sebastien Bacher (seb128) wrote :

Thank you for your bug report. The issue is an upstream one and it would be nice if somebody having it could send the bug the to the people writting the software (

Changed in gnome-control-center (Ubuntu):
importance: Undecided → Low

I'll take a read later and figure out how to report it.... but do they read launchpad bugs right?

this is an output of "xrandr -q"

santiago@hyperion:~$ xrandr -q
Screen 0: minimum 320 x 200, current 1280 x 800, maximum 1280 x 1280
LVDS connected 1280x800+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1280x800 60.0*+
   1280x768 60.0 +
   1280x720 60.0 +
   1024x768 60.0 +
   1280x600 60.0 +
   1024x600 60.0 +
   800x600 60.0 +
   800x480 60.0 +
   640x480 60.0 +
CRT1 connected (normal left inverted right x axis y axis)
   1280x800 75.0 +
   1280x1024 75.0 +
   1152x864 75.0
   1024x768 75.0 70.1 60.0
   1024x600 60.0
   800x600 72.2 75.0 70.0 60.3
   800x480 60.0
   640x480 75.0 72.8 60.0

notice that CRT1 is the 32" LCD TV and it appears to be an 1280x1024 resolution that is in fact not supported by the TV that is 1280x800 pixel display. Also for the 1024x768 the 60Hz frequency is available.

This issue is present with the opensource ATI driver as well as the propietary one that i downloaded yesterday. How can i add the 60Hz frequency for the 1280x800 resoluton??? i tried editing xorg.conf with no sucess

affects: gnome-control-center (Ubuntu) → xorg-server (Ubuntu)
Bryce Harrington (bryce) on 2010-07-02
Changed in xorg-server (Ubuntu):
status: New → Confirmed
Bryce Harrington (bryce) wrote :

The xrandr output is taken from the TV itself, so if it is reporting that it can do 1280x1024, X will try to use that resolution. The way to solve this is to teach the kernel to not provide that resolution for this particular piece of hardware using a 'quirk'. Unfortunately since no X or kernel logs are included it's not possible to construct this.

Are you still able to reproduce this behavior on Ubuntu Precise? If you don't want to install Ubuntu Precise, it should be sufficient to boot a Live USB session, configure the monitors, and see if it is working properly now. You can get the current Live USB desktop image at and create a USB boot drive using usb-creator.

If it still occurs, please attach your /var/log/Xorg.0.log, the output of 'xrandr --verbose', and the output of 'sudo dmesg > dmesg.txt'.

Changed in xorg-server (Ubuntu):
status: Confirmed → Incomplete
Bryce Harrington (bryce) wrote :

We're closing this bug since there has not been a response from the original reporter. However, the issue still exists please feel free to reopen with the requested information. If you're not the original reporter, we'd prefer you file a new bug report.

Some tips:

  * Report bugs via the command: `ubuntu-bug xorg`

  * Test against the latest development Ubuntu.
    Bugs marked as affecting the development version tend to get priority attention.

  * The `xdiagnose` utility has functionality for enabling debugging and
    analyzing a few common X problems.

  * Tag your bugs with the Ubuntu versions you have reproduced the issue in.

  * See for tips on writing good bug reports.

Changed in xorg-server (Ubuntu):
status: Incomplete → Expired
To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers

Related blueprints