Samsung SyncMaster 720N working only @60Hz

[Matthias Hopf]

On Apr 08, 08 13:42:12 +0300, Laszlo Kustan wrote:
> This model isn't in the list of monitors,  I tried to set the horizontal and
> vertical refresh ranges according to the monitor's manual:
> Synchronization
> Horizontal 30 ~ 81 kHz
> Vertical 56 ~ 75 Hz
> Resolution
> Optimum resolution 1280 x 1024 at 60 Hz
> Maximum resolution 1280 x 1024 at 75 Hz
> Maximum Pixel Clock
> 140 MHz
> 
> I tried to generate modeline with the proper settings, but the generator
> gives me only bad data (pixel clock too big)
> This is the vesa preset from the manual:
> VESA, 1280 x 1024 79.976 75.025 135.00 +/+
> this is the modeline I tried:
> Modeline "1280x1024" 135.00 1280 1296 1440 1688 1024 1025 1028 1066 +HSync
> +VSync
> but it does not work.

Where did you get this modeline from? This is neither conformant to GTF,
nor to CVT. You should use the 'gtf' and 'cvt' tools to calculate
modelines. E.g. you should try this one:

  # 1280x1024 @ 75.00 Hz (GTF) hsync: 80.17 kHz; pclk: 138.54 MHz
  Modeline "1280x1024"  138.54  1280 1368 1504 1728  1024 1025 1028 1069  -HSync +Vsync

If that doesn't work, try a 72Hz one:

  # 1280x1024 @ 72.00 Hz (GTF) hsync: 76.82 kHz; pclk: 132.75 MHz
  Modeline "1280x1024"  132.75  1280 1368 1504 1728  1024 1025 1028 1067  -HSync +Vsync


Also, if your driver is RandR capable, chances are high that your
monitor section isn't used at all.

Matthias

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Matthias Hopf <mhopf at suse.de>      __        __   __
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