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External monitor no longer wakes from sleep (10.11.2 update)

I have an external LG LED-LCD panel connected to my Mac Pro 2013 via HDMI.


No problems with display sleep at all before... but since updating to 10.11.2, it just does not wake from sleep and I have to force a reboot. I have since turned display sleep options off and I now use a password-protected screensaver instead (for security), and just switch my monitor off with the power button.


I had this problem also with Beta 2 and Beta 5 of 10.11.2. Both times I reverted back to 10.11.1 from Time Machine, hoping it would be fixed in the final release.


Before anyone says it, the following link is not welcome... I didn't come down in the last shower: If your Mac doesn't sleep or wake when expected - Apple Support


It's definitely something that has changed in El Capitan 10.11.2. I now have a $10,000+ beast of a computer that can't put its own display to sleep 😝

Mac Pro, OS X El Capitan (10.11.2), Late 2013 model

Posted on Dec 10, 2015 7:27 PM

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88 replies

Jan 20, 2016 8:14 AM in response to DaemoNZ

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?

Jan 20, 2016 8:27 AM in response to DaemoNZ

I have installed the 10.11.3 update and I still have a problem I believe is the same as this: when the MBPr "wakes" (it doesn't go to sleep, but turns off the screens) usually my two external monitors don't show anything, or just flashes of noise. The MBPr screen doesn't show anything, but it's turned on (you can see the backlight). Usually for the first moments I can see the login screen on my main external display, but then the "bands of noise" and everything goes dark.


What I have done since started to have this problem (don't remember with what update) is to turn off the external monitors. This usually makes the MBPr screen show finally the login screen. Once it is showing there, I turn on my external monitors, the MBPr recognizes them, changes the displays alignments, and I can work.


A few times I have just had to kill the computer, but it has been fortunately not that many times.

Jan 21, 2016 7:36 PM in response to DaemoNZ

Macbook Pro 15", OS X Version 10.11.3, BenQ FP202W Display


The OS update did nothing to solve the problem for me. Sometimes rotating the display in preferences helps, sometimes not. It usually just takes time, like half an hour, then switching the monitor off and on again brings it back.


Has Apple even acknowledged the problem yet? One of the main reasons for buying Macs is that they just work straight out of the box. But not in this case.

Feb 3, 2016 11:20 AM in response to DaemoNZ

Unfortunately after upgrading to 10.11.3, my Eizo Ev3237 4k monitor won't wake up after sleep, the system clearly knows the monitor, led light turn white, just no signal coming out. My rig is Macbook Pro 2015 with Radeon M370x.


I have 2 Screens connected to Macbook through mDP, the Dell U2415h works just fine, but no luck for the be loved 4k Monitor.


Anyone got a solution?

Feb 4, 2016 9:07 AM in response to DaemoNZ

I'm seeing a similar issue, that was not present prior to upgrading my 2012 Mac mini to El Capitan 10.11.3. Even with Apple's latest patch, the two external monitors for my 2012 Mac mini are exhibiting behavior that is different from Yosemite, which originally worked perfectly. Both monitors are standard HD (1920x1080) Asus PB238Q models. The primary monitor, connected to the Mac using HDMI, wakes up consistently. While the secondary monitor, using DisplayPort, fails to wake up. As a terrible workaround, I've found that opening System Preference > Displays then clicking [Gather Windows] and rotating the second display's image 90 degrees wakes it up, and then I just click "revert" to ignore the change. It gets the second monitor to respond, but it's a pain to do that each time the system goes to sleep. The problem is also somewhat inconsistent. If I tap the space bar or arrow key on the keyboard immediately after the system goes to rest, it will usually wake up with both monitors active, but after the system has been asleep for 5 minutes or more, the second monitor no longer comes back online. The problem did not exist in Yosemite and I'm considering going back.

Feb 28, 2016 7:59 PM in response to DaemoNZ

I Just had this happen on a brand new macbook pro 2.8 - everything was working great, had 2 display port to dvi monitors going via tbolt dock and an hdmi monitor, really working nice! Then i rebooted and none of them show up, rebooted and tried all kinda stuff, finally got 1 of the dock monitors on but when i pkugged in the 2nd it kills the first. Not been able to get all 3 running again... Le sigh, im supposed to wow my client that bought the mac for me tomorrow...

Mar 27, 2016 3:34 PM in response to DaemoNZ

I have a MacBook Air (early 2014) and I don't know if this issue started with 10.11.3 or 10.11.4 since I updated both at once from 10.11.2 -- but I can say I now have this problem -- the external monitor (which was working perfectly until I updated) is no longer recognized when I wake the MBA up after closing the lid.


After much trial and error, it seems I can get it working again by disconnecting the monitor cable from the adapter; note that disconnecting the adapter from the MBA or the cable from the monitor doesn't make any difference; neither does powering everything off and restarting.

External monitor no longer wakes from sleep (10.11.2 update)

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