It is not uncommon, especially for monitors that do not reply to DDC probe requests from the driver, to end up causing the driver to pick a mode that is not well suited. In this case, the fix is usually to tell Xorg what horizontal and vertical sync frequencies are appropriate for that monitor.
This is done in lts.conf with: X_HORZSYNC X_VERTREFRESH and example would be: X_HORZSYNC = 30-80 X_VERTREFRESH = 55-75 The exact appropriate values can be found on the data sheet for the monitor. However, if you are into guessing, you can try the values above and play with them. Alternatively, you can get a shell on the client and red the Xorg log file in /var/log on the client to find out what modes it rejected and why and what mode it put the driver into. If you know you want 60 Hz, you can also restrict the X_VERTREFRESH = 60 or 55-65 or some such. WARNING: With old CRT monitors, forcing incorrect sync frequencies could damage the monitor. With that said, the default/preferred means of setting *resolutions* and desired refresh rate and rotations, etc are with xrandr. The XRANDR_SIZE_0 is for drivers that do not support Xrandr1.2, and XRANDR_MODE_0 is for drivers that support Xrandr1.2. Xrandr will try to set the mode you specify and fall back on one of the known modes if it cannot. To absolutely, positively force Xorg to ONLY be aware of a SINGLE mode, you can use: XRANDR_DISABLE=True X_MODE_0 = <mode> where <mode> is a valid mode name that the driver knows. HTH, -Gadi On Fri, 2009-09-04 at 15:01 -0600, David Burgess wrote: > I've been reading through some recent threads on xranadr versus older > methods of setting screen resolution, but I can't seem to make any of > the recorded methods work on a cerain monitor. > > Ubuntu 9.04 x86_64 > HP thin client > HP L1506 LCD monitor > > When I boot the tc with a vanilla lts.conf, all appears to go well > right up to the point where X should start. The screen goes black and > the monitor's OSD says "Input signal out of range. Change resolution > to 1024x...@60hz". > > So I tried combinations of the following in lts.conf: > > XRANDR_SIZE_0 = "1024x768" > > XRANDR_MODE_0 = "1024X768" > > XRANDR_DISABLE="True" > X_MODE_0="1024X768" > > I think I threw in some thing like VERTREFRESH=60 or something like > that at one point, but I lost track of that reference. > > So with any of the above, my 15" monitor still complains that the > signal is out of range. When I force those settings on a different 17" > monitor they are effective in an ldm or rdesktop login. > > I'm confused. Is the monitor telling xorg something that makes it > override my settings? Any thoughts? > > db > > ------------------------------------------------------------------------------ > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > _____________________________________________________________________ > Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: > https://lists.sourceforge.net/lists/listinfo/ltsp-discuss > For additional LTSP help, try #ltsp channel on irc.freenode.net -- -------------------------------------------------------- Gideon Romm | Proud LTSP Developer l...@symbio-technologies.com Pay It Forward! Intel Atom 1.6GHz, 512MB RAM + Symbiont Boot Stick = $275 10% of order goes to school or open source project of your choice! Buy yourself a lab or office and use your donation to set up a school, pay for a desperately needed feature added to a software package, or sponsor part of LTSP's annual developer's conference LTSP-by-the-sea! Check out: http://www.symbio-technologies.com/payitforward ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _____________________________________________________________________ Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: https://lists.sourceforge.net/lists/listinfo/ltsp-discuss For additional LTSP help, try #ltsp channel on irc.freenode.net
