Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: How do I set display resolution on old monitor?

  1. #1
    Join Date
    Aug 2007
    Beans
    241
    Distro
    Ubuntu 10.10 Maverick Meerkat

    How do I set display resolution on old monitor?

    I have a new PC which I upgraded to Lucid Lynx a week or so ago. Since then though the display resolution appears to be set too high, or something so that all I see are flickering bands going up and down the screen.

    Am I right in thinking that in this new release a lot of the display stuff is now incorporated into the kernel, so the old option of adding settings to xorg.conf no longer helps?

    The PC has an Intel IGP, the monitor is an old Cornerstone CRT.

    Has anyone got any suggestions for me to try and get the graphics working correctly?

    At the moment all I can do is use the TTYs on Ctrl-Alt-F1 etc.

    Thanks in advance

    edited to add: when I connect up a more recent flat screen, the display works fine, and I can set all the supported resolutions of the monitor. The Cornerstone, being older, doesn't supply full data via plug-and-play (I think) and hence a too high resolution or frequency is being used.
    Last edited by lightstream; April 22nd, 2010 at 01:16 AM. Reason: more detail

    include <lightstream.h>

  2. #2
    dino99's Avatar
    dino99 is offline Ubuntu addict and loving it
    Join Date
    Jun 2006
    Location
    Nux Jam
    Beans
    Hidden!
    Distro
    Ubuntu Development Release

    Re: How do I set display resolution on old monitor?

    try sudo dpkg-reconfigure -phigh xserver-xorg

    or follow links in my signature

    maybe you have to add into xorg.conf the horizontal & vertical refresh rates of your display

  3. #3
    Join Date
    Nov 2007
    Location
    New Zealand
    Beans
    1,222
    Distro
    Ubuntu Development Release

    Re: How do I set display resolution on old monitor?

    You can create an xorg.conf file using..

    Code:
    sudo Xorg -configure
    see this thread for details..
    http://ubuntuforums.org/showthread.p...Xorg-configure
    Last edited by robert shearer; April 22nd, 2010 at 09:27 AM.

  4. #4
    Join Date
    Aug 2007
    Beans
    241
    Distro
    Ubuntu 10.10 Maverick Meerkat

    Re: How do I set display resolution on old monitor?

    thanks for that. still haven't cracked it though.

    It turned out I did have an xorg.conf, but with fairly empty looking entries.

    I deleted it, and rebooted to no effect.

    Then I ran sudo Xorg -configure which actually created a file called xorg.conf.new in my home directory. I copied that to /etc/X11 as xorg.conf and rebooted, and finally I tried sudo dpkg-reconfigure -phigh xserver-xorg but still the same thing.

    include <lightstream.h>

  5. #5
    Join Date
    Nov 2007
    Location
    New Zealand
    Beans
    1,222
    Distro
    Ubuntu Development Release

    Re: How do I set display resolution on old monitor?

    Have you edited your new xorg.conf file ?.

    You will need to find the vertical and horizontal refresh rates for your monitor and add those to the monitor section.

    Then when you reboot the xorg.conf file will be used to set the rates you have input and your monitor should work.

    So, step one find those rates..Manufacturers website, book that came with the monitor, google ??

    Once you have those if you need help from there then post back and we can step you through.

    It is simple and will work, provided you have the correct rates. (the wrong rates can damage the monitor.)


    note that sudo dpkg-reconfigure -phigh xserver-xorg no longer applies to recent releases.

  6. #6
    Join Date
    Nov 2007
    Location
    New Zealand
    Beans
    1,222
    Distro
    Ubuntu Development Release

    Re: How do I set display resolution on old monitor?

    See this thread for editing xorg.conf.
    http://ubuntuforums.org/showthread.php?t=83973

    Scroll down to
    How to edit or add HorizSync and VertRefresh lines
    for an example of what you will be adding.(just an example, you will need to use the data for your monitor.)
    Last edited by robert shearer; April 22nd, 2010 at 10:22 PM. Reason: added link....

  7. #7
    Join Date
    Aug 2007
    Beans
    241
    Distro
    Ubuntu 10.10 Maverick Meerkat

    Re: How do I set display resolution on old monitor?

    well I seem to have got somewhere but it really seems like it isn't looking at the xorg.conf file at all.

    I managed to dig up an old xorg.conf that had settings for this monitor and copied them over, but the display was exactly the same mess of flickering lines.

    I found this article online which said to add i915.modeset=0 to the Grub boot parameters, and then the system booted and the video was working at last (wahey! thanks for all the suggestions guys .

    At first I thought it was now picking up the xorg.conf settings until I checked the display options and found a completely different set of resolutions to those I'd supplied, and also only 60Hz was present as the refresh frequency for all of them.

    So to test this I deleted xorg.conf (well renamed it) and rebooted, and sure enough the system still works ok.

    I don't really get what this kernel modesetting is all about (note this machine had Jaunty Jackelope on until I put the new mobo in, at which time I then upgraded to Karmic and then Lucid.

    I still don't really get why the system started up OK in Karmic, as it was then apparently that kernel modesetting (whatever that is) was introduced for Intel (and ATi). In Lucid it is also extended to nvidia. So it seems odd that it was with Lucid that I started getting the video issue.

    I now need to find if there's some where I can change the frequencies available as xorg.conf is obviously being ignored!

    include <lightstream.h>

  8. #8
    Join Date
    Nov 2007
    Location
    New Zealand
    Beans
    1,222
    Distro
    Ubuntu Development Release

    Re: How do I set display resolution on old monitor?

    has an xorg.conf been generated after you renamed the old one ??

    If so what happens if you edit that ?

  9. #9
    Join Date
    Aug 2007
    Beans
    241
    Distro
    Ubuntu 10.10 Maverick Meerkat

    Re: How do I set display resolution on old monitor?

    when i renamed the existing xorg.conf and rebooted without one, a new one was not generated automatically.

    I had to run sudo Xorg -configure and then copy the file it created to /etc/X11.

    But it just seems that whether or not there's an xorg.conf in the right place, and regardless of what it contains, my system is booting up with some other settings that it's getting from somewhere else as the display only works when that line is added to the GRUB boot parameters and the display resolutions available to X are always the same regardless of what appears in the monitor section in xorg.conf.

    So my question now is where are the settings for my hardware coming from if xorg.conf is being ignored??

    Is there something wrong with my setup if xorg.conf is being ignored, or is it to do with this new 'kernel modesetting' for video?

    include <lightstream.h>

  10. #10
    Join Date
    Sep 2009
    Location
    Paris France
    Beans
    213
    Distro
    Ubuntu Development Release

    Re: How do I set display resolution on old monitor?

    xrandr will give you the information. The best choice is marked by an *
    Example:
    Code:
    @ubuntu-desktop:~$ xrandr
    Screen 0: minimum 320 x 200, current 1440 x 900, maximum 4096 x 4096
    VGA-0 connected 1440x900+0+0 (normal left inverted right x axis y axis) 410mm x 256mm
       1440x900       59.9*+   75.0  
       1280x1024      75.0     60.0  
       1280x960       60.0  
       1152x864       75.0  
       1024x768       75.1     70.1     60.0  
       832x624        74.6  
       800x600        72.2     75.0     60.3     56.2  
       640x480        72.8     75.0     66.7     60.0  
       720x400        70.1  
    S-video disconnected (normal left inverted right x axis y axis)

Page 1 of 2 12 LastLast

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •