Siôn Dafydd

Q: External display only works with Macbook open?

I have an Acer AL2623W which works fine as an additional or main screen, but a second after you close the laptop the screen goes blank and it shows an 'input not supported' error. The Macbook stays on, it just doesn't drive the monitor alone. Re-open the Macbook and both work normally!

MacBook Pro, OS X Yosemite (10.10.2), 13" non-retina mid 2009

Posted on Feb 12, 2015 5:03 AM

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Q: External display only works with Macbook open?

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  • by joe_7399,

    joe_7399 joe_7399 Feb 13, 2015 1:25 PM in response to Siôn Dafydd
    Community Specialists
    Feb 13, 2015 1:25 PM in response to Siôn Dafydd

    Hello Siôn Dafydd,

     

    Welcome to the Apple Support Communities!

     

    I understand that you are using an external display with your MacBook Pro and when you close the display on your MacBook Pro, the second display turns off. It sounds as though your MacBook Pro may not be connected to power while using with display closed. Please read over the attached article for information on using a second display in closed-clamshell mode.

     

    How to use your Mac notebook computer in closed-clamshell (display closed) mode with an external display - Apple Support

     

    Have a great day,

    Joe

  • by sionfrombude,

    sionfrombude sionfrombude Feb 13, 2015 3:02 PM in response to joe_7399
    Level 1 (0 points)
    Feb 13, 2015 3:02 PM in response to joe_7399

    Hi Joe,

     

    Yes the MacBook is connected to the power, a USB keyboard is plugged in and a Bluetooth mouse connected.

    And I have followed the 'closed-clamshell' work instruction.

     

    Oddly when I connect to a Sony TV (using a display port to HDMI connector that uses a USB port for power) closed-clamshell works perfectly.

     

    Cheers, Siôn.

  • by Siôn Dafydd,Solvedanswer

    Siôn Dafydd Siôn Dafydd Feb 14, 2015 2:03 PM in response to Siôn Dafydd
    Level 1 (0 points)
    Feb 14, 2015 2:03 PM in response to Siôn Dafydd

    Hi Folks,

    Just had an idea that worked: I used LogMeIn Ignition on my iPad to control my clamshelled laptop that was generating an unacceptable display signal for the monitor. I disabled screen blanking and set the resolution for the remote session to the native resolution of the display! I am now back in business with a shut laptop and an external display!

    Cheers, Siôn.