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 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 nano /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.

Close all running applications, restart GDM (/etc/init.d/gdm restart). Another way is just to log out your ubuntu session and press Ctrl-Alt-Backspace in the login screen. Look if everything went fine.

If the specified display resolution - "1280x1024" in the case above - differs from the used virtual screen resolution, add a respective line in the Display subsection of xorg.conf:

Virtual 1280 1024 

If these changes did not help, you can always use:

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

to restore your system to the previous state.

You use the "nvidia" driver (Binary drivers)

It would seem that xorg cannot detect the possible resolutions when using the "nvidia" driver. For me, the only resolution I could use was my LCD's native resolution (1680x1050).

Here's how you fix this:

1) Make a backup of your /etc/X11/xorg.conf as shown in the previous examples

2) Open /etc/X11/xorg.conf as shown in the previous examples

3) Add the following line to your existing "Screen" section:

Option "UseEdidFreqs" "false"

If all else fails, try running the following command:

sudo nvidia-settings

Under Video Configuration set your resolution and refresh rate, click apply, then save X Config.

Well, it worked for me: Feisty, Intel i810 video & Widescreen LCD

Added by TonyS, 12 May 07

I impulsively bought a ViewSonic VG1930WM 19" widescreen LCD (at a distinctly newfangled 1440x900 native resolution) without considering the possible pain in making the low powered Intel i810 (82845G/GL) graphics in my old Compaq EVO desktop (and Feisty) talk to it...

It really was a hassle, but I've solved it and thought someone, somewhere, sometime might benefit from knowing how.

Just a wee note first that the "915resolution" solution described in the wiki above did NOT work. After fiddling for ages I got the mode installed and the GUI would come up OK, but the display was corrupt, with the left edge missing in action off the edge of the window, the top inch or so blank and the right hand side two inches peculiarly munted. Hopeless.

OK, here's what solved it for me...

If (like me) you've already broken X at this point and are staring at a blank screen you need to reboot (I had to use the power button hold-for-5-seconds trick), hit "escape" at the first mention of Grub on reboot, and choose to boot in Safe Mode. This boots to a command prompt. Scary for many for sure, but its not TOO painful from here, so stay brave.

First, install the newer Intel drivers. I'm not sure why these aren't installed by default, sure should be. I think you'll need Universe enabled:-

sudo apt-get install xserver-xorg-video-intel

It asks if you want to replace the old drivers. Yep, you sure do.

Then run the xserver video autodetect thingy:-

sudo dpkg-reconfigure xserver-xorg

Choose all the autodetected and default settings it offers, with these exceptions:

1. At one point it asks about allocating system memory to the video card, making specific mention of the the i810. I'm not sure if it made any difference, but I set this to 64000 KB.

2. When it lists the resolutions you want enabled MAKE SURE your monitors native solution (in my case 1440 x 900) is checked.

Now you must reboot. You can do this by typing (wait for it...) "reboot". Nice.

This time let it boot as normal. With any luck it'll pop back up beautifully. In my case it came up 1024x768, so I went to System | Preferences | Screen Resolution and chose 1440x900, which worked perfectly.

GDM 1440x900 @ 75Hz on Viewsonic VG1930WM and Intel 946GZ

Added by VivekKapoor, 10 November 2007

Update: The following method worked, but when I logged out, I couldn't see the gdm screen. I had to switch to Virtual Terminal by pressing CTRL+ALT+1 and then restart the machine. But YMMV. I got a nVidia GeForce 7300 GT to solve the problem and it works smooth!

I bought a new VG1930WM monitor and spent a few days getting 1440x900 in GDM. I was successfully able to get 1440x900 @ 75Hz in my desktop as I was able to change it via the "System -> Preferences -> Screen Resolution". However in GDM it was using 60Hz. Due to this there was around 150-200 pixel blank space on the left of the screen. The motherboard is Asus P5B-MX WIFI-AP and the graphics chipset is Intel 946GZ. The Operating System is Ubuntu Gutsy Gibbon 7.10.

The solution was to use 915resolution and i810 driver instead of the stock intel driver and 16 bit resolution. Here's what I did.

1. Got the hsync and vsync from

   • sudo ddcprobe | grep monitorrange

2. Got the Modeline for xorg.conf from

   • root@Marqus:~# gtf 1440 900 75
     
       # 1440x900 @ 75.00 Hz (GTF) hsync: 70.50 kHz; pclk: 136.49 MHz
       Modeline "1440x900_75.00"  136.49  1440 1536 1688 1936  900 901 904 940  -HSync +Vsync
     
     root@Marqus:~# 

3. Added it in xorg.conf. The relevant sections from xorg.conf are

   • Section "Module"
     Load "i2c"
     Load "bitmap"
     #Load "ddc"
     Load "dri"
     Load "extmod"
     Load "freetype"
     Load "glx"
     Load "int10"
     Load "vbe"
     EndSection
     
     
     Section "Device"
             Identifier      "Intel Corporation 82946GZ/GL Integrated Graphics Controller"
             Driver          "i810"
             BusID           "PCI:0:2:0"
     EndSection
     
     
     Section "Monitor"
             Identifier      "VG1930wm"
             Option          "DPMS"
             HorizSync       30-82
             VertRefresh     50-75
             # 1440x900 @ 75.00 Hz (GTF) hsync: 70.50 kHz; pclk: 136.49 MHz
             Modeline "1440x900_75.00"  136.49  1440 1536 1688 1936  900 901 904 940  -HSync +Vsync
     EndSection
     
     
     Section "Screen"
             Identifier      "Default Screen"
             Device          "Intel Corporation 82946GZ/GL Integrated Graphics Controller"
             Monitor         "VG1930wm"
             DefaultDepth    16
             SubSection "Display"
                     Depth   16
                     Modes   "1440x900_75.00"
             EndSubSection
     EndSection

4. Installed 915resolution through

   • apt-get install 915resolution

5. Configured 915resolution

   1. Listed the available resolution on the screen

      • 915resolution -l

   2. Chose the mode 5c

   3. Edited /etc/default/915resolution and put the following entries

      • #
        # 915resolution default
        #
        # find free modes by  /usr/sbin/915resolution -l
        # and set it to MODE or set to 'MODE=auto'
        #
        # With 'auto' detection, the panel-size will be fetched from the VBE
        # BIOS if possible and the highest-numbered mode in each bit-depth
        # will be overwritten with the detected panel-size.
        MODE=5c
        #
        # and set resolutions for the mode.
        # e.g. use XRESO=1024 and YRESO=768
        XRESO=1440
        YRESO=900
        #
        # We can also set the pixel mode.
        # e.g. use BIT=32
        # Please note that this is optional,
        # you can also leave this value blank.
        BIT=16

   4. Edited /etc/init.d/915resolution and put two extra variables VALHSYNC and VALVSYNC and added them as parameters while starting 915resolution

      • PATH=/sbin:/bin:/usr/sbin:/usr/bin
        PROG=/usr/sbin/915resolution
        NAME=915resolution
        DESC=915resolution
        VBETOOL=/usr/sbin/vbetool
        VALHSYNC=30-82
        VALVSYNC=50-75

        From /etc/init.d/915resolution (Modified Line 7 below and added $VALHSYNC and $VALVSYNC

        case "$1" in
          start|restart|force-reload)
                echo -n "Starting $DESC: "
                if [ "$MODE" = "auto" ] ; then
                    auto_select_modes
                else
                    $PROG $MODE $XRESO $YRESO $BIT $VALHSYNC $VALVSYNC
                fi
                echo "$NAME."
                ;;
          stop)

6. That's all, I restarted the machine and it worked!

Problem related to DVI-Interface

After I upgraded my machine to Ubuntu 8.04 I was stucked with a maximum screen resolution of 800x600. No matter what I tried, nothing helped. I worked through suggestions on this page, but nothing helped. Finally I stumbled over another site where this problem was discussed and a user there described the same issue that I had. His solution was to connect the monitor cable not to the DVI port but to the VGA port of the card. I tried it and immediately my problem was gone.

(I'm using a BNC cable to connect my monitor to the computer. Maybe this is the reason why the monitor modes could not be recognized by Ubuntu on the DVI port.)

Adjust Only Resolution Settings on Dell Laptop

1. All I needed to do was get my laptop to display a higher resolution than 800x600. When I went to Syestem -> Preferences -> Screen Resolution, it was only showing me 800x600.

2. MAKE a backup of your /etc/X11/xorg.conf.

3. Open up terminal and type: sudo dpkg-reconfigure -phigh xserver-xorg.

4. I left mine on vesa (since I knew that driver was working) and select "ok".

5. This is the fun part, go through and select the screen resolutions you want enabled by default. Whatever you check here should end up in the dropdown list in Syestem -> Preferences -> Screen Resolution,

6. Restart X server (CNTRL+Alt+Backspace).

7. It started up in the highest resolution that I had selected (1440x900). No need (for me) to install nvidia drivers.

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 Ubuntu Support Forum or in the #ubuntu IRC support channel on the irc.freenode.net network.

CategoryCleanup