topic Re: X server issue with lcd monitor in Operating System - Linux

X server issue with lcd monitor

palaniappan.sp — Mon, 30 Jul 2007 01:39:55 GMT

Hi all,
I am facing an issue in X server running on RHEL4ES.X server is getting corrupted
frequently after few months of installation of OS.
the error i'm getting when i switch over to graphical mode is given below
Invalid input...when i try to start startx
not able to start x server and input to monitor not supporting...

Is it due to monitor resolution issue?

somedays b4 we were using crt 19inch monitors,then we change to 15inch lcd monitors.It was working fine w/o any issue for 2 months..

Pls let me know how can i bring back x server to my server..

regds,
palani.

Re: X server issue with lcd monitor

Yogeeraj_1 — Mon, 30 Jul 2007 01:56:46 GMT

hi Palani,

Can you try to recall the previous configuration file and retry?

# cp -p /etc/X11/xorg.conf
/etc/X11/xorg.conf.backup.$(date +%a)
# cp -p /etc/X11/xorg.conf.backup /etc/X11/xorg.conf

hope this helps!

kind regards
yogeeraj

Re: X server issue with lcd monitor

Matti_Kurkela — Mon, 30 Jul 2007 05:01:01 GMT

The problem is probably the refresh rate.

When using a CRT monitor, the display controller must send the picture to the monitor with a fairly high refresh rate so that the screen does not flicker and your eyes won't get tired fast.

Some people are more sensitive to the flicker than others, but generally with CRT displays, a refresh rate of 60 Hz is barely acceptable and 75 Hz or above is good. The most flicker-sensitive people may need 85 Hz or above.

With LCD displays, the flicker problem does not exist, so the refresh rate just sets an upper limit of how fast the picture on the screen can change. If something changes at a rate of 60 Hz or above, it is generally impossible to see anything but a blur. So the higher refresh rates are not really needed with LCD displays.

The problem is that the LCD displays generally support lower refresh rates than CRT displays: some LCDs accept only 60 Hz refresh rate, the better ones may go up to 75 Hz but very few accept anything above that.

So the signal that is _good_ for a quality CRT is _bad_ for a LCD, and vice versa.

You need to reconfigure your display settings for LCD. The system will then sense the capabilities of your LCD and will use refresh rates that are more suitable to a LCD display.

You should run the command "system-config-display" as root when the system is in text mode. This will activate the display configuration interface, just like when the OS was installed.

MK

Re: X server issue with lcd monitor

palaniappan.sp — Mon, 30 Jul 2007 22:55:23 GMT

Hi matti,
I already tried system-config-display in text mode ,there is no use..
When i try this command screen goes black color and indicating that invalid input...

pls let me know anyother way to get rid out of this probs..

yogeeraj,
I didn't try ur option but today i will do it and let u know the result..

regds,
palani

Re: X server issue with lcd monitor

palaniappan.sp — Mon, 30 Jul 2007 23:11:32 GMT

Hi Yogeeraj

I tried ur option its not working..let me know anyother possibilities.

regds
palani

Re: X server issue with lcd monitor

Rick Beldin — Tue, 31 Jul 2007 08:26:28 GMT

The /var/log/Xorg.0.log may have some clues.

If you grep it for 'WW' you get all warnings and if you grep it for 'EE' you get all errors. That might yield a clue.

Attaching that file to this thread might be helpful as well as your /etc/X11/xorg.conf