LCD screen thinks 1920 x 1200 is a 4:3 resolution

greengrocer · 05-23-2009, 03:44 AM

Hello all,

I am running Ubuntu, using Gnome desktop and am using the nvidia-glx driver for an Nvideo Geforce MX420 video card.

I have a Samsung 2443BW, 24" widescreen LCD monitor.

I have my screen resolution set to 1920 x 1200.

This setup was working fine for a month and now, without touching anything, the monitor today shows black bars over the left and right edges of the screen.

I can boot the computer into Windows and everything is fine.

When I set my screen resolution in Linux to a 4:3 ratio, I can see all objects on my Gnome desktop. When I switch back to 1920x1200 resolution, I cannot see objects at the edges anymore.

It actually seems that the monitor thinks that it is being fed 1280x1024 resolution.

The monitor has no way to adjust or force it to work with Linux.

Has anyone else had a similar experience?

Does the refresh settings in xorg make any difference for this problem?

And I repeat, Windows works at 1920 x 1200 resolution. So I dont think the monitor is faulty, but I am baffled as to how all of a sudden things dont work when they were not tampered with (all i did was switch my monitor on today and see things have gone haywire).

Regards,
Greenie

greengrocer · 05-23-2009, 09:16 AM

UPDATE:

I just tried a few versions of Ubuntu and discovered that:

* Ubuntu 7.10 Gutsy Gibbon actually drives the screen at 1920 x 1200 by default without a problem.
* No other version of Ubuntu will drive my screen at 1920 x 1200
* All versions of Ubuntu will drive the screen at 1680 x 1050 and the entire width of the screen is used.

Remember, Ubuntu 6.10 used to drive my screen at 1920 x1200, I changed nothing at all, no updates were applied, absolutely nothing changed to the O/S. I just booted up one day and discovered 1920 x 1200 was no longer working on my screen. so this is very very odd.

amani · 05-23-2009, 10:28 AM

graphics card driver?

consider custom xorg.conf

Shadow_7 · 05-23-2009, 09:35 PM

I wish my LCD had that many pixels. Normally it's a refresh rate thing for me, when using the same resolution between OS's. The different refresh rate requires different adjustments on the display device, and it's recall of recent modes doesn't share the settings, since they're not the same settings. Not so much an issue with LCDs though as they're pretty fixed in terms of resolutions and rates.

Perhaps the driver is misreading the EDID info from the LCD. Or the EDID info is just wrong and it's reading it just fine, but not compensating for the errors. Upgrading your monitors EDID, or graphics driver should help. Which the other version of Ubuntu probably has in place which is why it works. Otherwise you can force modes in contradiction to the EDID in your xorg.conf (modelines). Check /var/log/Xorg.0.log between the two versions and see what's different.

As far as aspect ratio, if it's the media player, you can aid it's interpretations. mplayer -monitoraspect 1.6 ..... I know I've had issues on my laptops LCD and ATI's xv driver. Oddly the issue doesn't happen if using -vo x11. Although I need to add -vf scale to play videos full screen without padding when using x11. Although it doesn't sound like this is your particular aspect ratio issue. Just mine on my 1280x800 Laptops LCD.

greengrocer · 05-23-2009, 11:23 PM

UPDATE:SOLVED

Thanks for the replies guys. I was kind of forced to dump Ubuntu 6.10 Edgy Eft (finally) because none of the official repo's were alive anymore.

I liked Edgy because for the computer in question, I used Xine a lot on it and Edgy had the best version of Xine I have seen to date. All later versions of Xine kind of suck due to usability problems when not running Compiz (Xine GUI cannot be summonsed whilst in fullscreen for example).

So I did the following:

1) Installed Ubuntu 8.10 Intrepid from the CD-ROM.
2) Downloaded the driver install script for GeForce2 - MX420 card from Nvidia: NVIDIA-Linux-x86-96.43.09-pkg0.run
3) Downloaded using synaptic manager linux-headers-generic and linux-source-2.6.27

Or

Code:

sudo apt-get install linux-headers-generic linux-source-2.6.27

4) Switched to TTY1 (eg CTRL+ALT+F1)
5) stopped GDM

Code:

sudo /etc/init.d/gdm stop

6) Ran the Nvidia driver install script

Code:

sudo sh NVIDIA-Linux-x86-96.43.09-pkg0.run

The Nvidia script mentioned something about some missing source code (I didnt quite read it all because I was in a hurry), but it offered to download whatever it was that it needed, so I just permitted it to do what it needed by answering 'Yes' to the prompts (which is lame not to read, I know, but it worked for me).

7) Edited and added the "1920 x 1200" and "1680 x 1050" modes into the 'Screen' section of xorg.conf so the video related stuff looks like this:

Code:

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       30.0 - 110.0
    VertRefresh     50.0 - 150.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
        Modes      "1920x1200" "1680x1050" "1600x1200" "1280x1024" "1024x768" "800x600" "640x480"
    EndSubSection
EndSection

8) Started GDM again

Code:

sudo /etc/init.d/gdm start

9) Changed screen resolution to "1920 x 1200", which initially did not work properly (black columns at left and right of the screen obscuring things such as the applications menu and the clock/calender, hence looks like 4:3 ratio)

10) Changed screen resolution to "1680 x 1050" which gave me full widescreen (but not native resolution)

11) Changed screen resolution back to "1920 x 1200" and the Ubuntu desktop was now displayed at full 16:10 wide screen (not sure why second time it decided to work properly, I'd love to understand why though).

So now computer and Samsung 2443BW happily working in harmony again, user now has to put up with dodgy version of Xine though.