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Multiple Displays have problems with El Capitan

I upgraded to El Capitan last week. Immediately after restarting from the install, my 2nd and 3rd monitors no longer displayed anything. It's like they were turned off. I tried restarting, but nothing changed. I then tried switching cables to different ports and seeing what would happen with just a single monitor plugged in, here's what I found.


Machine Info:

MacPro

32GB RAM

AMD FirePro D500 3072 MB Graphics


27" Apple Cinema Display (x2) using Thunderbolt

13HD Wacom Cintiq using HDMI


-------------------------

When 1 monitor was plugged in, it would work fine.

When 2 were plugged in, only the first monitor would work

It seems that changing ports made no difference, only 1 monitor would work at any given time. I also had issues with some external drives failing to mount.


I called AppleCare and they had me reset the SMC on the MacPro. This seemed to fix it until I setup my second cinema display with Apple Calendar and Apple Mail in the new split view and quit the applications without exiting SplitView first. Doing this blacked out the second Cinema display and I had to repeat the SMC reset procedure (listed below). It happened again about an hour later after a restart, I called AppleCare again and the tech led me through the SMC reset steps again and all monitors began working properly again. Within the next few hours the same problem happened again...I am now back on Yosemite until I see something indicating this problem is fixed.


I noticed that Beta users had this problem documented quite a bit on the .3 release, but I saw that the .4 release seemed to fix the issue. Well, it did not. I caught lightening in a bottle and it's happening to me.




SMC Reset Procedure

1. Shut Down computer if it's not already shut down

2. Unplug all peripherals and computer for 30 seconds

3. Plug in computer to power and one monitor

4. Start-up and check to see if monitor is working

5. If monitor is working then plug-in second display and restart


This worked for me and I was able to plug up the other peripherals.


I'm not sure why the problem persists, but everything is completely stable and operates fine on Yosemite.

Mac Pro, OS X Yosemite (10.10.5), iMac 27" 8GB i7

Posted on Oct 5, 2015 9:34 AM

Reply
156 replies

Nov 10, 2015 12:01 AM in response to Luis Sequeira1

Have you heard of this issue....


I have 3 displays rigged to a Mac Pro 13. 2 Acers connected via thunderbolt and a Vizio 4k TV via HDMI. Everything works fine when I have the 2 acers plugged in, i am able to scroll across both monitors and access the space. When I plug the Vizio into the hdmi, my 3 displays are there, but i am not only able to use the Vizio 4k and cannot drag my cursor anywhere onto the other screens. I went into System Preferences > Displays > Arrangement only to find no windows to arrange. They just simply aren't there. I tried detect displays and nothing happens. Any ideas how to work around this? I will attach images.


Vizio display main window

User uploaded file


Acer Displays that I cannot get to


User uploaded file

User uploaded file


The display adjustment windows show, but i am unable to do anything on those windows..


please help!


Thanks!

Nov 10, 2015 12:08 AM in response to JJROOKS

I am not sure it helps, but did you make sure the three displays are in separate Thunderbolt buses?

The HDMI port and the two lower TB are on bus 0.

The two TB ports up on the left are on bus 1, the two up and right on bus 2.

I would try setting the two Acers so that one is on bus 1, the other on bus 2.


Let us know if this solves the problem.

Nov 10, 2015 2:18 PM in response to Luis Sequeira1

Right? How strange of a glitch.


I did try all of those methods, and yes with 2 I can arrange, the second I plug in the 3rd monitor the screens refresh and im only able to use the TV and the arrange windows vanish.


I just recently purchased this computer, Thursday nov 5th to be exact. Weird thing is while I was setting up my monitors for the first time, all 3 worked and I was able to see the arrange windows. They were out of place and I tried to set them up in correlation with my monitors physical placement. It was then while I was tweaking the adjustments, they seemed to be tossed out of the window in all directions and vanished, rejecting any refresh I tried. I am using the mini dual link adapters for my both of my acers and direct hdmi for the vizio. This setup worked with my Mac Pro 2010 running Yosemite just fine. I'm assuming its some weird glitch in 10.11.1 that needs to be resolved.

Nov 11, 2015 3:17 AM in response to JJROOKS

The fact that it worked at first leads me to think that maybe some cache or other thing got corrupted.

You may try booting in Safe Mode and then restarting normally to see if it fixes it.


If that does not work: looking at your screenshots again it looks like there is no menu bar in the two inaccessible displays.

Try going to System Preferences->Mission Control, and check "Displays have separate Spaces"; log out and log in again to make that setting take effect, and see if this changes anything. If it works, and you prefer it the old way, uncheck that box, log out and in again, and hopefully it may remain working.

Nov 13, 2015 7:14 PM in response to Mattzda3

After downloading new drivers, the external monitors hooked up through USB ports worked great --- for about 15 hours. Now two of the three monitors lose their signal and just go blank. The weird thing is the computer still recognizes that they are there. So it appears they are communicating with the computer but they just go dark. If I restart the computer, they come up but after a few hours, go dark again. Any suggestions would be appreciated.

Nov 16, 2015 12:34 AM in response to apleased

Mid 2014 Macbook Pro Retina, just upgraded to El-Capitan


Never had any trouble connecting to normal Full HD LED TV (LG) using HDMI before upgrade.


No problem with automatic detection, but now the image on the LED TV flickers, is off-colour, and switching between windows using Command Tab is slow (freezes for up to 1 sec). Also crashed my entire machine once when toggling between Powerpoint (slideshow) and Chrome.


Pretty sure this is a bug with El-Capitan. Hope Apple solves this quickly.

Nov 16, 2015 1:02 AM in response to Luis Sequeira1

IMAC 27 Late 2012

Nvidia GeForceGTX 675MX

El Capitan 10.11.1


BENQ E2420HD connected via HDMI to Thunderbolt


This secondary screen set up was working fine until I upgraded to El Capitan.


The first issue I have is when I turn my computer on with the screen plugged in, it boots to a grey screen, however I can still login by guessing where to press and input my password.


The second issue is, once I am logged in I get unexpected shutdowns. The computer can only be restarted if I unplug the power cord. The shut down will usually happen within 20 mins of the computer being turned on.


The computer works fine if I don't have the secondary screen plugged in, no grey screen on login and no unexpected shutdowns.


Any suggestions ??

Multiple Displays have problems with El Capitan

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