[SOLVED] Monitor not displaying resolution properly

**power.supply** · September 6th, 2008

High All,
I am after a little bit of help if I can get it. I am running a 17 inch Philips monitor (107T4) with a radeon 9200SE video card on a fresh install of Ubuntu 8.04. My problem is this, when I try to run my monitor at 1280x1024 the screen gets a barely recognisable (ie really fast) flicker and a bar of random colours down the right hand side. One thing I have notice is that, according to the resolution selecting tool (ie System > Preferences > Screen Resolution), Ubuntu detects my display as a Philips 15" monitor. I am assuming, and correct me if I am wrong, that it has got the vertical and horizontal scanning frequencies wrong. The refresh rate that it chooses is correct for this monitor so I can only assume that this is the problem. Or is it video card related?
So, I have run

Code:

gksu displayconfig-gtk

and have found out that my beloved

Code:

sudo dpkg-reconfigure xserver-xorg

does not work with Hardy

. When I run displayconfig-gtk my monitor is not in the list. I have all of the necessary display settings for this monitor, so is there a way I can manually add my monitor to this list? Failing that, what else can I do?
Hear is the contents of my xorg.conf:

Code:

Section "InputDevice"
	Identifier	"Generic Keyboard"
	Driver		"kbd"
	Option		"XkbRules"	"xorg"
	Option		"XkbModel"	"pc105"
	Option		"XkbLayout"	"us"
EndSection

Section "InputDevice"
	Identifier	"Configured Mouse"
	Driver		"mouse"
	Option		"CorePointer"
EndSection

Section "Device"
	Identifier	"Configured Video Device"
	Option		"UseFBDev"		"true"
EndSection

Section "Monitor"
	Identifier	"Configured Monitor"
EndSection

Section "Screen"
	Identifier	"Default Screen"
	Monitor		"Configured Monitor"
	Device		"Configured Video Device"
EndSection

Section "ServerLayout"
	Identifier	"Default Layout"
	Screen		"Default Screen"
EndSection

Thanks in advance.

**power.supply** · September 7th, 2008

Thud...oops sorry, BUMP.

**thebigfatgeek** · September 7th, 2008

Hi Power.Supply

For what it is worth, I have had endless problems with my video card configuration, and did everything everybody ever wrote about setting it up, and it still did not work.

In the end I found that my monitor was not providing the correct EDID (Extended Display Interface Data) to the video card, and that caused the video card to "ignore" whatever I had in my xorg.conf.

In the end I had to manually set the video card such that it ignores the EDID data for it to work. It may just work for you too. I paste the relevant section of my xorg.conf for you here:

Code:

Section "Device"
    Identifier     "Nvidia"
    Driver         "nvidia"
    Option "IgnoreEDID" "TRUE"
    Option "UseEDID" "FALSE"
    Option "UseEDIDFreqs" "FALSE"
    Option "UseEDIDDpi" "FALSE"
    Option "ModeValidation" "NoEdidModes"
    Option "DPI" "96 x 96"
EndSection

Just make sure you have configured your monitor's horizontal and vertical frequencies in your xorg.conf to prevent any potential disasters. My full xorg.conf is as follow:

Code:

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 1.0  (buildmeister@builder3)  Thu Feb 14 18:20:37 PST 2008

# xorg.conf (X.Org X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
#   sudo dpkg-reconfigure -phigh xserver-xorg

Section "ServerLayout"
    Identifier     "Default Layout"
    Screen         "Default Screen" 0 0
    InputDevice    "Generic Keyboard" "CoreKeyboard"
    InputDevice    "Configured Mouse"
EndSection

Section "Module"
    Load           "glx"
EndSection

Section "InputDevice"
    Identifier     "Generic Keyboard"
    Driver         "kbd"
    Option         "XkbRules" "xorg"
    Option         "XkbModel" "pc105"
    Option         "XkbLayout" "gb"
EndSection

Section "InputDevice"
    Identifier     "Configured Mouse"
    Driver         "mouse"
    Option         "CorePointer"
EndSection

Section "Monitor"
    Identifier    "L1715"
    HorizSync     30-80
    VertRefresh   56-70
    Modeline "1280x1024@60" 114.98 1280 1312 1744 1776 1024 1045 1055 1076
EndSection
        
Section "Device"
    Identifier     "Nvidia"
    Driver         "nvidia"
    Option "IgnoreEDID" "TRUE"
    Option "UseEDID" "FALSE"
    Option "UseEDIDFreqs" "FALSE"
    Option "UseEDIDDpi" "FALSE"
    Option "ModeValidation" "NoEdidModes"
    Option "DPI" "96 x 96"
EndSection

Section "Screen"
Identifier "Default Screen"
Device "Nvidia"
Monitor "L1715"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1280x1024@60" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024@60" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024@60" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024@60" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024@60" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024@60" "1024x768" "800x600" "640x480"
EndSubSection
EndSection

According to Philips (www.p4c.philips.com/files/1/107e4374/107e4374_dfu_aen.pdf), this should be the specifications for your monitor, which you can use to set up your xorg.conf:

Technical Specifications CRT
• Size and deflection 17 inch / 41 cm ; 90° deflection angle
• Dot pitch 0.27 mm
• Horizontal pitch 0.23 mm
• Tube type Shadow mask, flat square, high contrast, anti-glare, anti-static, anti reflection, light transmission 47%

107E Product Information

• Phosphor P22
• Recommended display area 12.0" x 9.0" / 306 x 230 mm
• Maximum display area 12.9" x 9.7" / 327 x 245 mm

SCANNING
• Horizontal scanning 30 - 70 KHz
• Vertical scanning 50 - 160 Hz

VIDEO
• Video dot rate 108 MHz
• Input impedance
- Video 75 ohm
- Sync 2.2 kOhm
• Input signal levels 0.7 Vpp
• Sync input signal
Separate sync
Composite sync
• Sync polarities Positive and negative

WHITE COLOR TEMPERATURE
Chromaticity CIE coordinates:
• at 9300 degrees K x = 0.283 / y = 0.297
• at 6500 degrees K x = 0.313 / y = 0.329

**power.supply** · September 7th, 2008

Thanks for the info. I will give it a try. I was really hoping not to have to rewrite my xorg.conf file and somehow put my monitor into the list in the displayconfig-gtk utility. I figure if this is the direction that auto detecting is going in Ubuntu, it would pay to get my monitor added so then, when I upgrade, I don't get the same problem.
Edit: I also am not sure what everything in the xorg.conf file means and what needs to be added to get it to function properly.

**thebigfatgeek** · September 7th, 2008

I suppose even if your monitor is added to displayconfig-gtk, if the monitor sends the wrong EDID info at the point of configuration, the correct info there may not help, as it seems the driver just ignores xorg.conf and uses whatever the screen tells it. But then again, I am no expert in this matter, and I would like to hear from others on their views.

**power.supply** · September 13th, 2008

Got this problem solved. Using

Code:

gksu displayconfig-gtk

. I chose Philips 107b from the list, from the specs these closely line up with my monitor. I selected 1280x1024 at 60Hz then tested and it seemed to work properly. So I saved it into my home directory, logged out then in again and monitor works perfectly.

**smallman26** · September 22nd, 2008

Just wanted to say something here after 2 days of frustration, followed by great triumph.

Basically, no dual monitor/screen xorg.conf got my external Samsung 1600x1050 to run at resolution in Intrepid. (I had been using Xinerama with Hardy with success.)

The solution was to use the xrandr capability, as described here:

http://navetz.com/v/132/Simple-dual-...n-Ubuntu-Linux

This solution didn't work until I was brave enough to hotplug the monitor after booting up the laptop. In fact, I got blank screens if I booted up with the monitor connected.

After plugging it in and turning it on, issuing the commands below makes it all work.

sudo xrandr --auto
sudo xrandr --output VGA-0 --left-of LVDS

Or, if you want to move the laptop around, you can turn off the monitor, disconnect it, and

sudo xrandr --auto