iMac with dual screens - Having trouble

Discussion in 'Mac Accessories' started by SteelBlueTJ, Apr 8, 2014.

  1. SteelBlueTJ macrumors 6502

    Joined:
    Apr 2, 2012
    Location:
    USA
    #1
    I have an Asus PB278Q connected to my late 2013 27" imac via mini display port to display port in order to get the maximum 2560x1440 res. it works great however does have one weird issue. I dont use the Asus all the time, so i keep it turned off and only turn it on when i need the extra screen real estate. When i wake up the imac from sleep, it behaves erratically. The imac screen comes on then dims and the cursor moves without touching anything then goes to a dark gray screen - almost black (like it is searching for a display). Anyone know why it does this? Now i tried putting the imac to sleep with the asus display on and both went to sleep and woke absolutely fine. The imac only does this when i turn the asus display off. Its like the imac doesnt know what to do when it wakes from sleep when the asus is off. Anyone have any ideas? Thanks
     
  2. Altemose macrumors G3

    Altemose

    Joined:
    Mar 26, 2013
    Location:
    Elkton, Maryland
    #2
    Is this an Apple adapter you are using? I had an issue with a rather cheap adapter I ordered off the Internet where it would wake my HP S2031 improperly with similar symptoms.
     
  3. SteelBlueTJ thread starter macrumors 6502

    Joined:
    Apr 2, 2012
    Location:
    USA
    #3
    I'm not using an adapter. Its a mini-display port to display port cable i got off amazon for cheap. I dont think its the cable since i previously had a 24" dell u2412 hooked up the same way and everything worked great. Not sure why all of the sudden the new Asus 27" is causing sleep issues with the iMac.
     
  4. Mr Rabbit macrumors 6502a

    Mr Rabbit

    Joined:
    May 13, 2013
    Location:
    'merica
    #4
    I second the aftermarket cable being the issue idea.

    At work we use a standard set of third party displays (Lenovo, Samsung or Acer) with all of our Macs. One of our employees bought their own mini display port to DVI cable to use with one of the displays, rather than using the Apple mini display port to DVI adapter that we order with most Macs. Every few weeks or so I get a call from them asking about odd sleep/wake/display issues. The issue has lasted across multiple displays and two Macs (including the new one before we moved their data over).

    The only time it seemed to be better was when I secretly switched the cable for a DVI cable and Apple mini display port to DVI adapter. A few days later I got a trouble call from them, when I investigated I found that they had switched back to their own cable.

    That's just the most recent story, over the years I've seen lots of faulty third party display cables. If it's convenient I would recommend buying an Apple branded adapter and trying that. Worst case is it doesn't work and you can return it within 14 days.
     
  5. Altemose macrumors G3

    Altemose

    Joined:
    Mar 26, 2013
    Location:
    Elkton, Maryland
    #5
    I would try resetting the monitor through the OSD menu. Hit the menu button and it should be under System Setup! Next I would try a new cable.
     
  6. SteelBlueTJ thread starter macrumors 6502

    Joined:
    Apr 2, 2012
    Location:
    USA
    #6
    I tried everything I could think of to get this to work. My iMac has the 775M 2GB graphics card btw. My iMac still won't wake from sleep correctly when the ASUS is connected and turned off. I get a blank backlit screen until I power on the ASUS. So far I've tried...

    -reset SMC
    -reset PRAM
    -I even ordered another brand mini display port to displayport cable to see if that was the issue (same results)
    -Phoned Applecare and got no solution - they were as stumped as me and say its related to the Asus firmware. (no ASUS firmware updates available for Mac)
    -Phoned Asus support and they said they were also as stumped. They say it must be an Apple software issue.

    So I give up and will be selling the Asus display and sticking with my iMac only for now. I don't use my secondary display all that much anyway, so I should be able to live without it.
     
  7. Altemose macrumors G3

    Altemose

    Joined:
    Mar 26, 2013
    Location:
    Elkton, Maryland
    #7

    The easy solution is to turn your monitor on before putting it to sleep. It seems to be an incompatibility but at least it's better than how Windows handles it.
     
  8. SteelBlueTJ thread starter macrumors 6502

    Joined:
    Apr 2, 2012
    Location:
    USA
    #8
    Yea I considered that, but I shouldn't have to settle for incompatibilities after paying a premium price for a 1440 display. After paying that much money it should work as expected. If I decide to try again, maybe I will try the Dell U2713HM.
     
  9. Altemose macrumors G3

    Altemose

    Joined:
    Mar 26, 2013
    Location:
    Elkton, Maryland
    #9
    Ah... That is a nice display. I only saw it for a short time but it was really sharp!
     

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