Re: URGENT! 7600CS (rev 02e1) stays black when screen via VGA extender
Just because this worked with older/different hardware doesn't mean that you're not running into a hardware limitation with the newer hardware. The signal tolerances for G7x based cards are far more restrictive (for performance & quality reasons) than in NV4x based cards.
If you can capture the EDID from your CRT, you could always instruct the driver to ignore the EDID (UseEDID set to false) and then just use a modeline based on the mode from the EDID that you wish to use. However, if your hardware is the problem, this also will not help.
What kind of CRT are you trying to use?
Have you confirmed that the problem is not present when connecting the CRT directly to the videocard without the VGA-extender and without a KVM?