Q: Multiple Displays have problems with El Capitan

Thank you for your kind words.

I am Portuguese, by the way :-)

How about a great Honorary American!

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

Acer Displays that I cannot get to

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

please help!

Thanks!

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.

unfortunately that didnt solve it. I tried multiple arrangements all over the thunderbolt hub and nothing seemed to work.

Weird glitch, so maybe try a few stupid things:

-turn mirroring ON and then OFF again.

-turn on only the Vizio and ONE of the two Acers. Does it work that way? Can you arrange them in System Preferences->Displays?

What if you then add the other one?

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.

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.

Booting in safe mode did it! I was beginning to think there would be no solution. Thanks so much for helping out me out!

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.

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.

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 ??

I had a similar issue with only one of two Thunderbolt 27" displays working with my Mac Pro after upgrading to El Capitan - I had also noticed the boot time had increased by 2 or 3 times. I spent a couple of hours on the phone with Apple Support and went through the PRAM and SMC resets with no success. We were about to do an erase and re-install (I was dreading this as it is my music studio machine with a ton of software on), and I noticed that one of the disks in the Lacie 2Big TB disk had been making some odd noise. On a whim I tried unplugging the unit, and re-booted - I noticed that the boot time reduced significantly, and both screens turned on just fine.

I checked the disks in the Lacie, and it turned out that one of them was bad. as soon as I replaced it and rebooted, all was fine, It seems to me that the boot script is having issues when something times out. In this case, it was trying to start a bad disk, and by the time it timed out, the second display was not being initiated. It seems this is a hardware and software issue.

Long story short, it's worthwhile unplugging all external devices and trying to boot up the machine (for me that was a trial as I had 5 TB and 4 USB connections in a specific order). If the issue still exists, it's software, or internal hardware related.

I had all the same problems with external displays but just got them to work fine again.

Inadvertently fixed it by restarting my mac and holding down the Alt/Option key during restart. Not sure why that worked but my two displays are working again.

princeakeem wrote:

 

I had all the same problems with external displays but just got them to work fine again.

 

Inadvertently fixed it by restarting my mac and holding down the Alt/Option key during restart. Not sure why that worked but my two displays are working again.

The option key is supposed to let you choose among possible startup disks.

Do you mean the Shift key? That would actually make sense: it would start in Safe Mode, which as a side effect would clear a number of caches, some of which might have been corrupted and contributed to the problem.