Mini displayPort to DVI adapter doesn't work with chained DVI to VGA adapter.

Discussion in 'Mac Accessories' started by aapl fan, Apr 29, 2010.

  1. aapl fan macrumors newbie

    Joined:
    Nov 7, 2009
    #1
    So I've got a Macbook Air, a cheap 3d party miniDP to DVI dongle I just got from ebay that's connected to a DVI to VGA adapter which is in turn hooked up to an old-ish VGA monitor. The monitor isn't receiving any signals, so I'm wondering if I'm right in concluding that this setup isn't supposed to work?
     
  2. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #2
    I think your MDP to DVI adapter is DVI-D, meaning that it can only carry digital signal while VGA is analog. You're better off buying a cheap MDP to VGA adapter than playing with it
     
  3. xraydoc macrumors demi-god

    xraydoc

    Joined:
    Oct 9, 2005
    Location:
    192.168.1.1
    #3
    Correct. The miniDP to DVI adapter only carries digital signals. No analog (VGA). You'll need the miniDP to VGA adapter for that.

    In other words, the DVI to VGA adapters don't really do any conversion. They simply pass the analog signal (if available) from the DVI cable to a VGA-shaped DB15) connector.

    The circuitry of the display port adapters will do either DVI or VGA, but not both simultaneously.
     

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