Refresh Rate Dell Optiplex GX270

tom_ dlist at
Tue Feb 8 18:31:09 CST 2005


This seems to be a more common problem than I thought and it took me
ages to nut out a solution.  The details of how I did are a bit
complicated but it is along these lines worked out by dare2dreamer

I would be interested in hearing if this solution works for you as if
it does it deserves a better fate and more prominance than simply being
repeated selectively 

Re: Screen Resolution Help
I think the advice contained in this thread may be helpful ......

The live cd's monitor detection routines (cribbed from morphix/knoppix)
have consistantly been better than the hardware detection routines in
ubuntu and other distros X installation. In the case of Ubuntu, I found
that it left you with X working, but at a refresh rate that was so low
it gave me headaches. So, I copied the monitor definition lines
(modelines) from the livecd's XF86Config-4 to a floppy and then cut and
pasted the relevant modelines into my hard drive install. Once the
modelines were properly in my XF86Config-4, I could get my resolution
up to 75mhz, or whatever it was my monitor supported (wasn't my machine
where this came up, so I don't remember offhand)

The warning came from a foolish attempt to wholesale replace the file.
Apparently, the layout of the XF86Config-4 is somewhat different. While
the modelines work, everything else won't and you are left with X in a
non-working state if you simply copy the file instead of just selecting
the relevant portions.

While there are tools for making the modelines out there within your
installation, I've yet to have found any that were easy to use.

How to fix monitor refresh rates in XFree86

01) Boot computer off Ubuntu Live CD
02) Copy /etc/X11/XF86Config-4 to a floppy
03) Reboot into Ubuntu Installation on HD
04) Copy modelines from floppy file into monitor section of

05) Restart X and reset refresh rate to something higher than 60hz

***WARNING: Only copy modelines sections. If you use live CD's
XF86Config-4 as is you will break your X installation.



Good luck



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