Two displays, one not waking up

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Level 1

18 points

Two displays, one not waking up

I recently installed two Dell U2414H displays on my mid 2011 Mac Mini. I have one connected directly to the HDMI output and the other to the mini-DisplayPort output using a DP > HDMI adaptor. I set the arrangement and set the menu bar to be on the right monitor. Everything was working fine at first but now when I power on the Mac Mini the right monitor doesn't always wake up. I have to power it off then on again and then it displays the login screen. The monitor in question is the one connected to the DisplayPort output on the Mini. Any thoughts on why this is happening. Is it something to do with DisplayPort? Thanks for your assistance. Also, this may not be related but it seems that after I setup the two displays the Mini keeps turning on the wi-fi connection which I have to turn off again, I have the Mini wired to my router with an ethernet cable. Strange.

Mac mini, OS X El Capitan (10.11.4), Corsair 128GB SSD, 16GB 1333 DDR3 RAM,

Posted on May 22, 2016 2:43 AM

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Answer 1

lllaass

Level 10

210,519 points

May 22, 2016 3:30 AM in response to sjc47

If you change the monitor connections does the problem follow the monitor of the Mac output?

If it follows the Mac connection then maybe a bad adopter. Googling shows that you monitor also has a displayport input. I would use that via a mini displayport>displayport cable

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Answer 2

sjc47 Author

Level 1

18 points

May 22, 2016 10:13 AM in response to lllaass

I swapped cables and it followed the monitor. I realized that the display came with a mini-DP to DP cable (after I already bought the mini-DP to HDMI adaptor!) so I used that. On first power up of the Mini both displays came on but I'll have to test it over the next couple of days. I also understand that you can daisy chain monitors using the Display Port connections but also read that it requires Display Port 1.2 capability and that certain Mac Mini's don't have that specification. Any way to tell if my Mac Mini would support that (Mid 2011 Mini). Thank you.

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Answer 3

lllaass

Level 10

210,519 points

May 22, 2016 10:21 AM in response to sjc47

Your Mac only support DP 1.1

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Answer 4

sjc47 Author

Level 1

18 points

May 23, 2016 11:34 AM in response to lllaass

I presume the newer Mini's support the DP 1.2 specification. So this morning when I powered up the system both screens came to life but both also had the login prompt. As soon as I entered my password the prompt disappeared from the left and went to the right as it should. I think I will try your software troubleshooting as a measure of system maintenance.

On another possibly related note, do you care to weigh in on whether or not Sophos Anti-virus for MAC creates more problems than its worth?

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