dual displays not working consistently

Discussion in 'Mac Pro' started by wdhpgx, Aug 13, 2006.

  1. wdhpgx macrumors newbie

    Joined:
    Aug 11, 2006
    #1
    So. New MacPro, and I'm having trouble getting my two displays working consistently. They are a pair of SGI 19" LCDs, which show up as "SGI F180". This is on a default-config MacPro.

    Sometimes they both come up fine. Sometimes one comes up fine, and the other is light blue, or mostly-black. Sometimes neither comes up: both blue, or both black, or one blue and one black.

    If I disconnect one it'll go blank of course, and then the remaining one will blank briefly and then come back -- either properly, or blue, or black, or sometimes white or dark blue or white with pink/yellow vertical stripes. When I reconnect it again, the previous one will blank again, and then both will come back -- either properly, or some mix or blue or black or white etc.

    If I disconnect and reconnect enough times, eventually I'll get both back up properly. Sometimes it only takes a couple times. Sometimes it seems to take a million times.

    Letting them displays power-save, or letting the machine go to sleep, will cause them usually to not come back properly.

    When one is not displaying properly, playing with the resolution settings for the blue/black display (via "gather windows") will sometimes make it reappear, but only for smaller resolutions (640, 1024, etc). Switching from a working-640 back to 1280 never makes it work.

    The 2-3 times I tried booting from the CD, the second display also didn't come up properly, so I don't think it's OS related (or else I would have tried re-installing).

    So .. Anyone seen anything like this before? Any .. known-meaning to the blue/black/white screens? Is there a .. better/easier way to reset the displays than physically yanking the cable? Does it sound like the video card might be bad? Ugh.
     
  2. me hate windows macrumors 6502

    me hate windows

    Joined:
    Jan 18, 2002
    #2
    Do the displays work properly connected to a different machine?
     
  3. wdhpgx thread starter macrumors newbie

    Joined:
    Aug 11, 2006
    #3
    I've never had a problem with them individually. But neither of the previous machines had dual-monitor outs (powerbook, linux server). As best I can recall, if I boot the macpro with only 1 of the pair connected, it works okay.
     
  4. me hate windows macrumors 6502

    me hate windows

    Joined:
    Jan 18, 2002
    #4
    Hmm. I have never seen a problem like that before. If both work individually it sounds like the computer is the problem. Do you have any friends with dual monitor jacks to plug them into? Or somebody else with a Mac Pro?
     

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