Moosbrugger

Q: Mac Mini Not Handling Two Displays

I've got a Samsung tv plugged into the HDMI of my Mac Mini (2015 model, current OS).  I bought a new Dell U2751H and plugged it into the thunderbolt port.  The Dell does not work correctly.  It keeps blacking out and switching resolutions.  It will work for about 5 seconds, then go black, then come on at a higher resolution for a "blip", then go black and then come back to the original resolution.  And repeat.

 

I find that the Dell works fine if I unplug the HDMI.   So, I think the Mini is sending a "bad" signal to the thunderbolt port when the Samsung tv is plugged into the HDMI.

 

I've looked at the Display option of System Preferences, but I don't see any settings that help me.

 

Any ideas?

 

I don't want to use the two displays as an extended display.  I want both displays (Dell & Samsung tv) to display the same image.  (I rarely use the Samsung as a display.  Only when I watch videos through the Mini.)

iTunes Match, OS X Mavericks (10.9)

Posted on Jul 26, 2016 5:11 AM

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Q: Mac Mini Not Handling Two Displays

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  • by JimmyCMPIT,

    JimmyCMPIT JimmyCMPIT Jul 26, 2016 5:15 AM in response to Moosbrugger
    Level 5 (6,973 points)
    Mac OS X
    Jul 26, 2016 5:15 AM in response to Moosbrugger

    if it doesn't work as an extended display does it work as a mirrored display?

     

    you may wish to try another resolution or the same resolution with a alternate synchronization timing if it's available.

    to access the hidden resolutions for the monitor bring up the display control panel under the system preferences

    >System Preferences>Displays

    click on the Scaled radio box while holding the OPTION key and choose an alternate display resolution.

  • by Moosbrugger,

    Moosbrugger Moosbrugger Jul 26, 2016 5:23 AM in response to Moosbrugger
    Level 1 (9 points)
    Apple Pay
    Jul 26, 2016 5:23 AM in response to Moosbrugger

    Cont.:  If I go into Displays under System Preferences, I see two display dialogues -- one for the Samsung and one for the Dell.  Under Display "Optimize for", I try to set the Samsung to "Samsung" and the Dell to "U2715h".  But the computer sets them both for the same optimization.  So, they're either both set to optimize for the dell or both for the Samsung. 

     

    That doesn't seem to be right.