external monitor resolution problem

[pkaplan1]

On Sunday 13 December 2009 06:48 Nik N wrote:
> I have a problem in setting an external monitor to its full resolution
> in 9.10 (64-bit). It worked in 9.04 (also 64-bit).
> 
> Hardware:
> Acer TM 5530 laptop with ATI/AMD FGLRX graphics driver.
> Samsung SyncMaster 204B (20", 1600x1200 native) external monitor.
> External monitor is connected with a vga->dvi cable from VGA external
> port to analog monitor input.
> 
> In 9.04 it took some 'fiddling' (multiple attempts, difficult to
> reconstruct) but in the end the external monitor worked at its full
> native resolution.
> 
> Using [Display Preferences] in 9.10 I can get the Samsung recognized
> ([Detect monitors]...), but when activated, its resolution list goes
> indeed somewhat higher (up to 1440x900)  than the "primary" laptop
> display (which is 1280x800). Oddly, on the expanded resolution list
> for the external monitor there is a  couple of blank, "unpopulated"
> rows above the 1440x900 row (not "grayed", simply blank) which can not
> be selected. It appears that those line would, if populated, go up to
> full resolution (1600x1200).
> 
> Questions:
> Is there something obvious I'm missing?
> Which X configuration file could be compared between two installs
> (9.04 and 9.10) to offer some insight.
> What would be the consequences of manual edit of such file?
> Anything else I could try?
> 
> 
> TIA, Nik N.
> 
Try xrandr.  https://wiki.ubuntu.com/X/Config

This should allow you to work out a suitable configuration on the fly.  Then you 
can create either a script to execute when needed or an xorg.conf file.