G5 Video


I have a dual 2ghz G5. When I boot up the video looks correct all the way up to the point where the system is finishes loading, then the color gets too saturated and bright. When trying to calibrate the monitor, auto calibrators fail to get good color, and Apple built in cannot achieve the correct brightness (the first stem to adjust the brightness fails to show the grey oval at all - even when the brightness is enough to wash out the screen). I have tried resetting the NVRam and has had no effect. I did stumble on to an odd fix, but it is not one I want to leave as a solution. If after I boot up (when the color is over saturated), I unplug and replug the monitor into the G5, the color returns to how it is supposed to be. At that point, the monitor can be calibrated normally, and everything is good. When I reboot, it reverts to being too saturated... unplug, replug and color is fine.

This happens no matter what color sync profile I choose. And the color shift seems to happen just prior to the color sync profile being applied.

So, does anyone know if there is a way (other than reseting nvram) to reset the video back to factory specs? I think that would resolve it.
I wish there was some response to this issue. I have exactly same problem with 2x 2Ghz G5's. Apple recommended changing the Video Card, unfortunately this was a waste of time and money. ATI pro support does not seem to know the answer either.
One more detail relating to this problem, when going into System Preferences, Displays, Colour - no profile is selected or selectable.
You have to re-plug the cable ...only after that the Display is detected and the profile selected by the system.
Any thoughts any one?
Thanks for the suggestion.
Unfortunately it did not help.
I will try resetting the P and Video Ram next, but if this does not help I'm stuck.
None of those 'fixes' will do anything to help. You have a setting that is too high in your Universal Access pref pane. Makes the display and the video appear unfixable. The clue is when the video looks OK until the OS completes loading, and then the video goes screwy.
Universal access/Seeing/Display - move the contrast slider to the far left (normal), and there you are.
This is a setting that you can accidentally adjust, and completely miss how it was done.

Another one is control-Option-Apple-8 - which reverses the screen, and causes all kinds of confusion if done accidentally. I helped someone whose cat had walked across the keyboard, toggling the reverse screen - they thought the cat had somehow ruined the video card!