Monitor Freezing + Not turning On. Dell U2711 on 2011 Macbook Pro via MiniDisplayPort

Discussion in 'MacBook Pro' started by glassflank, Apr 19, 2011.

  1. glassflank macrumors newbie

    Mar 31, 2010
    I am having the following trouble with this monitor.

    • When I turn the monitor off and the laptop is running, I cannot turn the monitor back on, it freezes, I need to unplug and replug the power to get it back on
    • When starting the laptop with the lid closed, it does not pickup the monitor, I need to unplug and replug the cable from the mini display port until it works, usually the monitor freezes at lease once while doing this
    • Sometimes the Apple Light on the back of the monitor screen/lid stays on when I have the monitor plugged in and the laptop lid closed, I am not sure what exactly causes this as it only happens sometimes

    I am running a cable that goes from the Mini-Display/Thunderbolt output on the laptop to the Display Port input on the monitor.

    As a workaround I have a 10 minute Monitor Sleep timer to turn the monitor off, as I cannot use the power button without freezing the monitor.

    Thanks for your help!

  2. snaky69 macrumors 603

    Mar 14, 2008
    This is not normal behaviour. If you can, I'd test the display with another similar computer to rule it out, else I'm thinking you may have a faulty laptop.
  3. ramw5p macrumors member

    Sep 29, 2010

    Im having similar problems. In clamshell mode monitor brielfy turn on..go through password, then back to sleep and wont wake up.....on hold with apple right now to talk about it
  4. ramw5p macrumors member

    Sep 29, 2010

    they are closed...bankers hours for my 350 for apple care...sigh
  5. glassflank thread starter macrumors newbie

    Mar 31, 2010
    Cool, let me know if you do find out what it is

  6. nanoguy macrumors newbie

    Apr 21, 2011
    I've got similar problems.

    For comparison, my Dell U2711 works just fine with my 2009 13" MacBook Pro via a Mini-Displayport to Displayport adapter cable.

    But using the same monitor with the same cable on my new 2011 13" MacBook Pro makes the Dell freeze! The Mac seems to recognize that an external screen is attached, but the Dell stays black. All of the five touch-button lights go off, the power button stays lit (blue), but none of the buttons shows any response (even after unplugging the displayport cable). I have to unplug the power cable of the Dell to get it back to life. But still, there is no way how I can use it with the Laptop.

    I have a gut feeling this has something to do with the new Thunderbolt? Does anyone have an idea how to fix this issue?
  7. glassflank thread starter macrumors newbie

    Mar 31, 2010
    The issue you describes is the exact same issue I have with my 2011 Macbook Pro, I recently had a 2009 Macbook pro (was stolen) and it did not have the issue.

    Looks like it is a problem with the new Macbook Pro's, I suspect the thunderbolt port as well.
  8. eonaeon macrumors member

    Feb 15, 2008
    Down Under
    I'm having the same problem with my 15" 2011 MacBook Pro and my new Dell U2711 Monitor as well... doesn't help the problem, but good to know it's not just me!
  9. EEXOOO macrumors regular

    Aug 1, 2009
  10. pmcm macrumors newbie

    May 9, 2011
  11. eonaeon, May 11, 2011
    Last edited: May 12, 2011

    eonaeon macrumors member

    Feb 15, 2008
    Down Under
    That fixed it for me, thanks for that:

    Menu->Other Settings->DDC/CI->Disable

    Edit: ok maybe not after all - if my MacBook Pro has been asleep for a while, it still won't wake with the monitor plugged in.
  12. nanoguy macrumors newbie

    Apr 21, 2011
    Update fixes this issue

    I have just installed Apple's most recent updates. Among them was one that is supposed to fix issues with Thunderbolt. Well, it actually worked for me. I can now use my Dell via Mini-DP to DP cable at full resolution.

    There is only one issue left: The screen freezes when I first connect the cable and then turn on the monitor (i.e. pressing the Dell power button). It also freezes when I turn off the screen before disconnecting the cable. But by simply reversing the order (first turn on screen, then connect cable; first disconnect, then turn off screen) everything is alright. :)

    Try it out!

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