Red Hat Bugzilla – Bug 437045
Resolution on external monitor is wrong with new vga cable
Last modified: 2008-06-04 02:44:48 EDT
Description of problem: I connected a new vga cable and now I can't use it because I get some really strange and wrong resolution on my external 19" monitor from my laptop. The resolution is 1280x800 but that is the resolution that my internal laptop screen has. External monitor worked on 1280x1024 with old cable. But that cable is too thin and I got a new one which is much thicker and gives me much better video quality. I have resolution switcher applet started (resapplet) and it offers me these resolutions: 1360x768 1280x800 1152x864 1280x768 1280x720 but nowhere on that list is 1280x1024 I started system-config-display and choose as monitor LCD 1280x1024 and testrated X.org but I got message that X can't be stated. I use X without xorg.conf but once I stated it made one. I'm attaching this xorg.conf that is not working and a log file of these activities. Why can't I force my screen to use 1280x1024 resolution? Cheers, Valent. Version-Release number of selected component (if applicable): How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Expected results: Additional info:
Created attachment 297676 [details] xorg.conf this is the xorg.conf with which my X don't even start. If I delete xorg.conf they start but with those strange resolutions I wrote in comment #1
Created attachment 297677 [details] Xorg.0.log
http://www.p4c.philips.com/files/1/190v6fb_27/190v6fb_27_pss_aen.pdf PDF with technical specs says that this monitor has: Maximum Resolution: 1280 x 1024 @ 75 Hz Recommended Resolution: 1280 x 1024 @ 60 Hz Video Dot Rate: 140 MHz Horizontal Scanning Frequency: 30 - 83 kHz Vertical Scanning Frequency: 56 - 76 Hz
I hard coded these specs in xorg.conf and now I can choose 1280x1024 with "resolution switcher applet" why doesn't X recognize my monitor correctly with different cable?
It doesn't recognize the monitor because the cable isn't passing the DDC signal correctly. We see EDID for the internal panel but not for the external VGA. Your cable is broken, in other words.
Thank you, you are right.