topic wrong resolution in Operating System - Linux

wrong resolution

Tonatiuh — Fri, 03 Mar 2006 10:58:21 GMT

Red Hat Enterprise linux 4

I had a monitor which support up to a 1280x1024 rsolution.

In system-config-display I saw major resolution (1600x1400) and I selected.

When I restarted the machine, monitor cannot whow image because the wrong configuration of the resolution display.

I have booted to init 3 and run the system-config-display again to tray to reconfigure the resolution (to 1280x1024) but it cannot show image because the same problem (wrong resolution configuration).

Any idea about how to resolve this problem?

Re: wrong resolution

Vipulinux — Fri, 03 Mar 2006 11:10:49 GMT

Hi
What monitor is it?
check for correct/updated display modules.

cheers

Re: wrong resolution

Tonatiuh — Fri, 03 Mar 2006 11:24:17 GMT

>What monitor?
Answer: View Sonic LCD

>check for correct/updated display modules
Answer: What are the display modules? could you be more specific?

Re: wrong resolution

Ivan Ferreira — Fri, 03 Mar 2006 12:50:49 GMT

Are you sure that your monitors supports that resolution? If so, ensure that you have selected the right driver (module) for your video adapter and the monitor type.

Re: wrong resolution

Sergejs Svitnevs — Fri, 03 Mar 2006 13:02:33 GMT

You need to login as root and change display resolution in /etc/X11/xorg.conf file. Then restart X.

Regards,
Sergejs

Re: wrong resolution

Sergejs Svitnevs — Fri, 03 Mar 2006 13:09:48 GMT

Sorry, under RHEL the configuration file is named /etc/X11/XF86Config

Re: wrong resolution

Tonatiuh — Fri, 03 Mar 2006 13:43:18 GMT

Hi Sergejs,

I have attached an xorg.conf file (not the one from the machine with the problem), because I do not know where to change the resolution currently configured.

could you help me with the line or value that represents the current resolution configured?

Re: wrong resolution

Renjith Nair — Sat, 04 Mar 2006 06:46:04 GMT

hi

There will be a section called Monitor,
It should be in 75th line, in that section you have to change the resolution

Re: wrong resolution

Tonatiuh — Sat, 04 Mar 2006 14:26:40 GMT

The line to fix is:

Modes "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480"

The original line showed resolutions not supported by my monitor. I just deleted all resolutions nos supported.

This line is in Section "screen"

Re: wrong resolution

John Collier — Thu, 09 Mar 2006 09:34:33 GMT

Just FYI for those who have not learned this as of yet.

In the xorg.conf (or corresponding file in RH releases or other distros), the first resolution listed in the string will be the default for your system on boot.

For example, let us just say that your monitor is able to do resolutions all the way up to 1280x1024. As long as you want to use the 1280x1024 each time you boot the system, then you will want a line just like the one that Tonatiuh has listed above.

However, if you would like to use, for example, 1024x768 as your default resolution but you still want to be able to change to the higher resolutions if needed, then you simply change the line to read:

Modes "1024x768" "1280x1024" "1280x960" "1152x864" "800x600" "640x480"

One word of caution.

If your monitor and display are not set for the monitor correctly at load and you add higher resolutions as your default later on, this can cause some inconsistencies and basic headaches for you later on.

For example, my system didn't recognize my particular monitor on load and gave me a default highest possible resolution of 1024x768. My monitor will easily go well beyond this. At the time of install, I did not worry about it too much simply because I knew I could add the lines to xorg.conf later and I proceeded to do just that after the install was complete.

While I was finally able to get this to work for me, it has messed up my GDM logon screen. Every time I need to reboot for any reason, where I should have a nice, pretty logon screen, I now see nothing more than an error message telling me that the frequency is out of range! I can still logon with username/password and the user desktops are functioning beautifully (if anybody out there knows how to fix this, I will GLADLY start another thread for it so that I may assign points and not hijack Tonatiuh's thread).

Hope this is helpful to someone.