Problem with display blanking out

I am presently experiencing a problem with my display. It keeps blanking out at a regular interval, approx. every 30 secs. This seems to have been a bit of a problem since I changed the computer but has got much worse a few days ago.

The monitor was previously used with an older machine running Mandriva. I changed it for a more recent machine (bought 2nd hand) and now running OpenSuse 11.4. There were no problems with the older machine but the new machine worked OK generally but the blanking occurred occasionally, like maybe once or twice a day.

Then last week it got a lot worse. Overnight the display changed, when I booted up in the morning the blanking began to occur every 30 secs and blanked for about 3-4 secs. The computer keeps working as, if I am typing it keeps entering text during the blackout. The screen resolution also changed from 1280px width to max 1024px although the display appears to have remained at 1280px wide because the toolbar at the bottom now extends beyond the screen. The screen resolution when I shut down was 1280px wide and had been fine for weeks but now the maximum resolution obtainable is 1024px wide. So I assumed it was a display/graphics problem.

I have upgraded the graphics card from a GeForce 7300 to GeForce 8400. The blanking now still occurs but only blacks out for a fraction of a second, and the screen resolution is still max. 1024px. I have tried another monitor with no improvement

Anybody have any ideas? Could it be, perhaps, a software problem? Any assistance welcome.

regards,
Mike

I have upgraded the graphics card from a GeForce 7300 to GeForce 8400. The blanking now still occurs but only blacks out for a fraction of a second, and the screen resolution is still max. 1024px. I have tried another monitor with no improvement

The driver in use may be relevant here. Did you try to install the proprietary nvidia driver yet?

Execute

/sbin/lspci -nnk

and post only the try pertaining to your graphics card.

Is the monitor an older CRT-type with VGA (D-sub15) connectivity?

Is this the right line?

01:00.0 VGA compatible controller [0300]: nVidia Corporation G98 [GeForce 8400GS] [10de:10c3] (rev a2)
Kernel driver in use: nouveau

Neither monitor was CRT.

regards,
Mike

I found a how-to at Nvidia Installer HOWTO for openSUSE users for installing the NVidia driver. This is done through Yast after adding NVidia downloads as a repository.

This all seemed to go OK but after rebooting it seems to have sorted the blanking but the monitor is still only recognised as max. resolution of 1024px.

Okay. Now we need to see the output of the detected available display modes.

xrandr

Now, it could be that your monitor is not providing the correct EDID to the driver (a common nvidia issue). There are workarounds for this (if this proves to be the case). Upload the lengthy output from /var/log/Xorg.0.log to
SUSE Paste
then post the link to it here.

Thanks Deano,

xrandr: Failed to get size of gamma for output default
Screen 0: minimum 320 x 240, current 1024 x 768, maximum 1024 x 768
default connected 1024x768+0+0 0mm x 0mm
1024x768 50.0*
800x600 51.0 52.0 53.0
640x480 54.0
512x384 55.0
400x300 56.0
320x240 57.0

Xorg log file @ SUSE Paste

From my uneducated look at the file it does appear that the EDID is not provided.

The monitor was working Ok after I first installed OpenSuse some months ago, I was using a screen resolution of 1280px width. It changed overnight, I shut down normally one evening and next morning it had changed.

Any help much appreciated.
Mike

From my uneducated look at the file it does appear that the EDID is not provided.

Yes, although the EDID is read in, the driver does declare that the header is invalid, and later

    18.567] (WW) NVIDIA(0): Unable to get display device CRT-1's EDID; cannot compute DPI
    18.567] (WW) NVIDIA(0):     from CRT-1's EDID.

This is a bug IMHO. Anyway, moving on from that, it will be necessary for some manual Xorg configuration. It is not difficult, but sometimes one has to try a few modeline entries, before reaching a successful result. The Xorg config files are located within /etc/X11/xorg.conf.d/ directory. Alternatively, one can still use the legacy /etc/X11/xorg.conf file (which is not present by default) with a minimal config. (The newer .conf files just contain separate sections, which were all included in the original xorg.conf file).

You can use the ‘cvt’ command line utility to generate modelines for a given resolution. For example, if your monitor is capable of 1280x800@60Hz, then you use cvt like this

> cvt 1280 800 60
# 1280x800 59.81 Hz (CVT 1.02MA) hsync: 49.70 kHz; pclk: 83.50 MHz
Modeline "1280x800_60.00"   83.50  1280 1352 1480 1680  800 803 809 831 -hsync +vsync

The entry can then be used within a minimal xorg.conf as illustrated in the following threads:

http://forums.opensuse.org/forums/english/get-technical-help-here/hardware/474616-monitor-resolution-not-recognized.html
http://forums.opensuse.org/english/get-technical-help-here/hardware/460441-11-4-higher-display-resolution.html

One has to take care, since a bad modeline will prevent the X-server (and desktop) from starting. You’ll then need to boot in ‘failsafe’ mode to get a graphical environment back. The offending entry will need to be removed or adjusted.

Here’s a way to play using the ‘xrandr’ command:

http://forums.opensuse.org/forums/english/get-technical-help-here/hardware/474119-solved-screen-flickers-wrong-resolution.html

Read them all first, and feel free to ask further questions if required.

Thanks again deano.

I found that the monitor would support a 1440x900 display so I created a modeline with cvt. Then created /etc/X11/xorg.conf using the suggestion in http://forums.opensuse.org/forums/en...esolution.html modified for 1440x900. Rebooted and it works.

I have now also realised that I don’t have sound as the speakers are on the monitor. Perhaps I will just connect up some other speakers rather than mess around further.

Thanks again deano.

I found that the monitor would support a 1440x900 display so I created a modeline with cvt. Then created /etc/X11/xorg.conf using the suggestion in http://forums.opensuse.org/forums/en...esolution.html modified for 1440x900. Rebooted and it works.

My pleasure. I’m glad you got the outcome you were looking for. Make sure you keep a copy of that working xorg.conf safe…maybe on a usb memory stick or similar. :slight_smile:

I have now also realised that I don’t have sound as the speakers are on the monitor. Perhaps I will just connect up some other speakers rather than mess around further.

Use what works for you :slight_smile:

Your Xorg hinted that your monitor was connected via VGA (hence CRT-1). Is that correct? Unless you had an audio cable connected between your monitor and your sound card, I wouldn’t expect to hear sound from your monitor. (However, if it was connected via HDMI, then audio and video can be carried).

The connection to the monitor is by VGA cable and separate audio cable. It did have sound before but not any longer.

If its an audio cable output to the monitor (and not an HDMI cable), then it should function like nominal speakers.

Did you try configuring with the application pulse audio volume control (pavucontrol) ? I documented my experience using pavucontrol in this blog: Pulseaudio Basics for openSUSE with pavucontrol - Blogs - openSUSE Forums