Problem with dual monitor setup since upgrading to El Capitan

Discussion in 'OS X El Capitan (10.11)' started by scottw75, Oct 9, 2015.

  1. scottw75 macrumors newbie

    Sep 18, 2014

    I have a 5k iMac and had been using an Asus monitor as a second screen since i got it last year. Since upgrading to El capitan and waking my iMac from sleep, sometimes the Asus screen stays off however the display settings in control panel shows it as connected. This was connected to the thunderbolt output of my iMac and did it on either output. Turing the monitor on and off fixed the problem.

    I yesterday upgraded the Asus monitor to the apple thunderbolt display and it's doing exactly the same thing! You have to restart the iMac to bring the second screen back as the thunderbolt display doesn't have an on/off switch.

    So is this a known issue with El Capitan and is there a workaround until an update is released? I could stop the machine sleeping i guess but that is hardly ideal.

    Thanks for any help
  2. dogslobber macrumors 68040


    Oct 19, 2014
    Apple Campus, Cupertino CA
    I've sometime had this problem via thunderbolt connected display on my MBP. I usually unplug the offending display then reattach. Interestingly, it's only one of the three external displays that has done this.
  3. scottw75 thread starter macrumors newbie

    Sep 18, 2014
    It's weird because the previous monitor was fine till I upgraded to el cap.
  4. dogslobber macrumors 68040


    Oct 19, 2014
    Apple Campus, Cupertino CA
    I remember snow leopard early builds had issues with my Dell LCDs not switching it on from sleep. The Mac mini 2012, had an early hdmi issue that was eventually fixed via firmware update. So hopefully it'll be fixed soon. Btw, I see the issue in beta builds of 10.11.1, so not soon enough.
  5. JJKH macrumors newbie

    Oct 30, 2015
    Not impressed, am falling out of 'love' with macs more each day. Yet another issue to deal with, VERY POOR from Apple
  6. MDW DESIGN LTD macrumors newbie


    Feb 17, 2017

    You all are not alone in these conundrums
    associated with El Crapitan, as I call it.

    this OS "Upg-raped" me, as I now have had to update multiple music production
    apps that were originally Power based PC software(s).

    Myseteriously, my HD has had issues, and I have had to do everything I could think of
    like wipe, reconfigure, back up, clone, and reinstall OS, as well as the HOKEY POKEY to get it running again.

    On top of all that, I also am having display issues as well. Keep in mind that ALL OF THESE
    issues were fully functional and operational, without glitch,
    while I operated on 10.6.8. Had to upgrade due to a hard drive failure
    which led to a plethora of domino effect issues.

    The back of my mac has 2 separate DVI display port outputs side by side in the back,
    with which I ran an apple cinema display and an HD LCD 32" side by side for a music production set up.

    On snow leopard, they work just fine. Upon booting from el capitan, only one works.
    When both are plugged in however, the apple cinema display goes black and it
    seems to favor the HD LCD. Regardless of which port is used for which.

    So now, as I wrote this, I had this idea, that it may be associated with the lack of
    support for those power-based pc apps.

    Now the OS might be telling the system that it cant support or power both
    simultaneously with out that "fancy shmancy" new dvi multi-port adapter BS.

    Probably wrong, but just a thought.

    Would Disabling the SIP fix this?
    OR updating the graphic card?
    OR do I just have to cave and buy one of those mother lickin display adapters??


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5 October 9, 2015