Thursday, November 7, 2013

Xubuntu 12.04 - Fix low screen solution issue

Early this morning, I installed a fresh Xubuntu 12.04 in a machine. After the computer booted up, the screen displays at 1024x768 mode. And I cannot changed to higher mode (actually, there was higher mode). So, I do the following steps to fix this issue:


1.Install this tool in a good machine (which is Xubuntu and does not have this problem) to get EDID (Extended Display Identification Data) of the monitor:

$ sudo apt-get install read-edid


2. Run the following command to get the  monitor information (EDID):

$ sudo get-edid | parse-edid


The results will be something like:

        # EDID version 1 revision 3
Section "Monitor"
        # Block type: 2:0 3:ff
        # Block type: 2:0 3:fc
        Identifier "DELL E1912H"
        VendorName "DEL"
        ModelName "DELL E1912H"
        # Block type: 2:0 3:ff
        # Block type: 2:0 3:fc
        # Block type: 2:0 3:fd
        HorizSync 30-83
        VertRefresh 56-75
        # Max dot clock (video bandwidth) 90 MHz
        # DPMS capabilities: Active off:yes  Suspend:yes  Standby:yes

        Mode    "1366x768"      # vfreq 59.790Hz, hfreq 47.712kHz
                DotClock        85.500000
                HTimings        1366 1436 1579 1792
                VTimings        768 771 774 798
                Flags   "+HSync" "+VSync"

        EndMode
        # Block type: 2:0 3:ff
        # Block type: 2:0 3:fc
        # Block type: 2:0 3:fd
EndSection


Take notes on the Mode, DotClock, HTimings, VTimings, and Flags parts.


3. Run the following command in the bad machine to get the current settings:

$ xrandr -q

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096
VGA1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 410mm x 230mm
   1024x768       75.1*     60.0 
   800x600        75.0     60.3 
   640x480        75.0     60.0 
   720x400        70.1 


Take notes the VGA1 (Device's name)


4. Create a file name 10-monitor.conf:

$ sudo nano /usr/share/X11/xorg.conf.d/10-monitor.conf

And add these following lines:

Section "Monitor"
Identifier "Monitor0"
Modeline "1366x768"  85.500000 1366 1436 1579 1792 768 771 774 798 +HSync +Vsync
EndSection
Section "Screen"
Identifier "Screen0"
Device "VGA1"
Monitor "Monitor0"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1368x768"
EndSubSection
EndSection




5. Reboot and change screen solution to the new added mode in Settings >> Settings Manager >> Display





References:

[0] http://www.bingshui.org/tech/defining-display-resolutions-in-xubuntu-12-04/
[1] http://www.ubuntugeek.com/how-change-display-resolution-settings-using-xrandr.html
[2] http://askubuntu.com/questions/61431/help-monitor-not-giving-proper-edid-information