Dual displays not remembering primary on boot

Discussion in 'Mac mini' started by mquinn, Jan 29, 2012.

  1. mquinn macrumors member


    Jan 29, 2012
    Normal, IL
    We are using a Mac Mini at our church to run Graphics/Videos. The HDMI connection goes into a video switcher, the display port to DVI goes into a projector.

    When the mini boots, even if we make the projector primary, it's making the HDMI port into the switcher the primary. In fact, unless we pull the display port and plug it back in, the mini doesn't even know the display port is there on reboot.

    Any thoughts?
  2. bradpole, Jan 29, 2012
    Last edited: Jan 29, 2012

    bradpole macrumors newbie

    Mar 27, 2011
    I have the same issue! I have dual monitors hooked up to the Mini. One is Mini HDMI to HDMI on the monitor, the second is thunderbolt to DVI adapter and DVI in on the monitor.

    Unless I pull either the HDMI or the thunderbolt out from the Mini before rebooting without fail the monitors on reboot will switch positions (the mini things the monitor that was on the left is now in the right and vice versa). Slightly annoying for moving windows between the two screens!

    I've tried different combinations of having the left monitor on HDMI and right on thunderbolt and vice versa but after each reboot they switch positions again.

    Thankfully I don't reboot frequently, but before I do each time I pull the thunderbolt monitor out from the Mini and plug it back in only after the reboot is complete.

    I have the Mini released this past July 2.7GHz Dual-Core Intel Core i7, with 8 gig Ram
  3. dolphin842 macrumors 65816

    Jul 14, 2004
    Sometimes resetting the NVRAM and reconfiguring the displays in System Preferences can help with this issue.
  4. bradpole macrumors newbie

    Mar 27, 2011
    Nope, same issue. Have to unPlug one display from the mini after booting, doesn't make a difference if right display is hdmi or thunderbolt, after rebooting the displays have switched sides

    Thank you for the suggestion, it was worth a try!
  5. dolphin842 macrumors 65816

    Jul 14, 2004
    That's weird, but not too unusual. One of my monitors, for instance, can lose a connection after the display goes to sleep.

    Another random thought: How long is the DVI cable going to the projector? If it's a long throw, the cable may be near the limit of DVI's range.
  6. mquinn thread starter macrumors member


    Jan 29, 2012
    Normal, IL
    Ok, here is a bit more detail.

    In one set up we have
    DP --> VGA which goes into a switcher
    HDMI --> DVI which is going into a monitor

    Second set up is
    DP ---> VGA which is going into a monitor
    HDMI ---> DVI which is going into a projector

    In both cases, we gave to pull DP out when the computer boots in order to get the primary monitor (which in both cases is the monitor) to display correctly. Any ideas?
  7. Ken Jeffries macrumors newbie

    Jul 13, 2012
    I just ran into the same problem. I am testing a Mini-DVI to VGA adapter. I *guess* that the common thread is VGA. Other than observation I have no evidence but it is possible that:
    1) the Mini Mac considers the VGA monitor to be inferior to the HDMI-DVI monitor and forces the HDMI-DVI monitor to be primary.
    2) the Mini Mac can't properly detect the VGA monitor through the Mini-DVI to VGA adapter and so forces the HDMI-DVI to be primary.

    BTW my Mini-DVI adapter is non-Apple. The one I have is less expensive and received better reviews than the Apple version.

    Just guesses. I know that when using the Mini-DVI to DVI adapter I don't have any problem.


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