Q: External monitor no longer wakes from sleep (10.11.2 update)

I am installing the 10.11.3 beta to test it. Will let you know in a couple of days, if it helps...

Same issue on mid-2012 15" macbook pro with BenQ FP202W monitor. Only happens when the hardware is asleep overnight, and waking the display up requires fiddling and waiting - same thing does not work each time. I will give the hot corners method a go.

Very disappointed to hear about the lack of customer support from Apple. Denying a problem or passing the buck does not fix it.

I have had so many issues and frustration with my dual display on my Mac Pro set up but thanks DaemoNZ heaps you made my life so much easier. I was thinking recently to sell my second monitor and buy another 4K. But your solution works man! Apple only fixes issues if we send them a feedback. Discussion forum doesn't do anything.

Cheers,

Matthew

Have exactly the same issue,  Late 2013 MacPro  running LG IPS Superwide 29" monitor connected via displayport to thunderport.   Machine goes to sleep but wont wake the monitor.

A work around that seems to work most of the time is to remove the thunderport and plug it into another bus port.  Luckily the Mac pro has 3 busses (6 ports).  but not what you would expect from a £5K machine. 

Come on Apple - with so many people with the same issue - fix the problem!!

I have a mid-2010 Mac Pro. Same issue with 2nd display (Samsung 22" with DVI). Has to be system software software. I also have new 27" iMac with 2nd display… same problem. Even with 10.11.4.

I called apple support tonight after reviewing this thread. Ive tried the following:

Reset SMC

Reset PRAM

Reinstall OSX

Still having issues with iMac with 10.11.2 and my Samsung 4k display and waking up from sleep. Apple support told me to update my monitor software... Also pointed out unless it was an Apple display I was SOL

I have found a temporary FIX to this problem. Reboot the Mac in safe-mode by restarting and holding SHIFT until boot. This will activate the slave screen but it will be inaccessible. This is ok. Once the computer has fully loaded all icons under the safe mode, reboot the computer and allow it to start normally. The slave screen will now be active and accessible. Remember if the screen slips into sleep then you will have to undergo this process all over again. My recommendation is to shut down the computer when you have finished working with it, this way it should start properly again.

It appears to be exclusively a problem with the sleeping function.

Best solution so far:

  1. System Prefs/ Energy Saver set computer and display sleep to 1 hr. 15 min.

  2. System Prefs/ Screen Saver set for 20 min.

  3. End of session, go to login window by clicking user icon upper right menu bar. Select "sleep".

This mostly works (MBP late 2011, El Capitan 10.11.2, BT LE4 installed), but occasionally fails.

    4. When it fails, open Displays Pref (through System Prefs or icon in menu bar). In "Display Port"  under "Rotation" select any-- 90°, 180°, whatever-- doesn't matter. After a few seconds, hit return, which will select the default to reject the rotation change. 2nd monitor lights up. This consistently works.

I installed 10.11.3 beta 2 (it's in public beta now) last Sunday, and I have not had any issues after that.

I have a an Apple Mini (mid 2011) and a Phillips TV connected via std. HDMI.

I'll let you know if the problem re-emerges.

But it seems that 10.11.3 solves the issue. The beta seems stable, but I only use it as a Media Center...

I understand that 10.11.3 fixes the problem, but just to record another solution in case anybody needs it...

I have a 2010 iMac Pro with a Phillips 24" LED second monitor, which of course was not waking up after sleep on 10.11.2.   I have just (after several days annoyance) discovered that the following works to awaken the second screen:

a) System Preferences > Displays (first tab)

b) Press the Opt / Alt key and a new button will appear on the bottom right, called something like 'Identify displays'. (Apologies, can't test it now for the exact name - in any case, click on the button that appears when you hold down the Opt key).

c) Click on that and the second screen will awaken.

Or, at least, it has done reliably for me so far.

Hope this helps somebody.

Just a head's up - The 10.11.3 is now out of beta and ready to install via app store.. I have run 10.11.3 beta for 10 days, and the previous problems with no screen after sleep has been gone...

So hopefully this update solves the issue...

Unfortunately, I have installed the latest 10.11.3 update, and this issue continues to persist for me.  The only fix that I've found reliably works so far is physically unplugging the monitor and plugging each piece of the cord back in individually.  Really really frustrating at this point.

Same problem. Different temporary solution.

If I go to display preferences and initiate a rotate to 90 from the drop down on my 2nd screen, then let the rotate expire without clicking any choices, the 2nd screen will stay on until i let it sleep. It then powers down completely.

While this won't help everyone...

My issue occurs on a mac-mini (connected to an Onkyo receiver by HDMI, which outputs via HDMI to a Samsung LCD) that I use for a media server and playback device.  I use Plex for this.  When I leave open the Plex Media Player fullscreen on the computer, I don't have display issues and can turn my system on/off hours to days apart and the display pops up no problem.  If I leave it on the OS X/Finder desktop, the issue reappears (irrespective if I use a screensaver, the rotation "Fix", the detect display "fix", the hot corners etc...), but only after my receiver (i.e. the "display") is off for a while.

This to me implies it has to be an issue with OS X/Finder... which may be obvious but I think this confirms up.

Sorry that this solution won't help everyone, but maybe there are other software workarounds?