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Level 1

10 points

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

88 replies

ciciroes

Level 1

14 points

Apr 16, 2016 9:01 PM in response to GinaBeana

Same as GinaBeana: unplug and replug the power cable. Resetting NVRAM did not help.

Apr 18, 2016 12:17 PM in response to ciciroes

Here's what finally worked for me -- changing the settings on the Energy Saver preferences and the Screensaver preferences, below.

Now, when the monitor goes to screensaver, it comes back when I press any key

When I'm done for the day, I set it to "sleep" (from the Apple drop-down menu), and it also comes back when I press a key.

Good luck!

Apr 25, 2016 1:06 PM in response to GinaBeana

I have the same issue on 10.11.4, and have had the issue for months. The only solution is to unplug everything, reboot, then plug in one at a time. Generally it only happens when I put it to sleep and disconnect wires to move my laptop. On reconnect, the second monitor won't come on. Sometimes it just occurs from sleep, regardless of connections.

I have a Mid 2015 Mac Pro Retina, Viewsonic HDMI monitor. FWIW, if I try to plug in a USB or DVI monitor in, it doesn't recognize those either.

May 26, 2016 8:23 PM in response to DaemoNZ

I too am seeing this after the latest update-

10.11.5

Mac Pro (Early 2009)

2 x 2.26 GHz Quad-Core Intel Xeon

24 GB 1066 MHz DDR3 ECC

NVIDIA Quadro 4000 2048 MB

IMRAN

Level 3

502 points

Jun 20, 2016 12:00 AM in response to DaemoNZ

Add me to the list of people facing this issue. My MacBook Pro Retina Late 2013 has a Thunderbolt to HDMI connector going to one external monitor and the laptop's HDMI going to a second external monitor (total 3 displays including laptop screen). For some months now I have had the HDMI connected monitor flicker on and off with a static discharge type sound. Then it will not happen for weeks. Nothing is moved or changed to cause a typical loose wire type problem. Less often but more annoyingly the Thunderbolt-HDMI connected one will just now wake up from sleep. The monitor is in sleep mode but the Mac sees it as connected. So, I cannot even bring up System Preferences (for example) even to play with the Monitors/Displays settings since the preferences window happened to have last opened on that display in question. In general the only way is to either pull out the Thunderbolt adaptor or toggle power on the display, which 'fixes' the problem but makes all the windows painstakingly separated out on to that display fall into the laptop display requiring each one to be re-dragged and resized back to that monitor. Very annoying to have to do that when one comes back to the desk wanting to jump into something quickly only to have to do this rigmarole. Hope someone has a good permanent solution. Regards Imran

Aug 15, 2016 5:08 PM in response to DaemoNZ

I've the same issue with DELL P23I4H via MiniDP-DP cable.

The Apple Support suggest to DISABLE 'Put hard disks to sleep when possible' in 'Energy Saver'.

It works for me.

markked

Level 1

8 points

Aug 23, 2016 9:14 AM in response to Bi11gates

Reporting in

Same issue as well. Got two 27" IPS screens from HP. One connected via mDP and the other HDMI.

When I put my system to sleep, and wake it up again - only the screen thats via mDP wakes up, the HDMI just keeps "attempting to wake" and make my mDP go black screen to wake again after several seconds, like it would try to recycle to wake. To make it all stop and work normally, I would have to take out and put back in the HDMI connection.

Im using 10.11.6 - Mid 2015 MBP

markked

Level 1

8 points

Oct 3, 2016 5:36 PM in response to markked

Was this ever resolved with macOS Sierra? I'm still having issues.

Oct 27, 2016 12:36 PM in response to DaemoNZ

Same issue here with Mac OS 10.12.1 (Sierra) / MBP Late 2012

It happened to me since I updated my Mac OS (maybe from 10.12.0 to 10.12.1)

Nov 17, 2016 9:21 PM in response to sydneyitguy

Also happening for me - Late 2012 MBP, 10.12.1 - external monitor lost after sleep, or simply unplugging it and replugging it. Just a black screen, but the laptop seems to detect it, as it changes the resolution.

I tried the SMC reset and PRAM reset - no luck

Any other ideas?

4nc4p

Level 1

4 points

Nov 26, 2016 5:28 PM in response to DaemoNZ

Same problem here.
MBP 13" Early 2013 with Samsung S27D850 Display via Display Port / HDMI.

This problem is NOT solved as the answer marked as "solved" suggests.
It is still an issue - open since December 2015.

idano

Level 1

4 points

Nov 30, 2016 2:40 PM in response to DaemoNZ

Same type of issue here.

MB Pro Retina 15" Mid 2014

macOS Sierra 10.12.1

Lid closed

Dual Acer 27" S231HL Displays

1 connected via HDMI

1 connected via Thunderbolt to HDMI cable

When trying to wake the computer via the Apple BT keyboard or mouse both displays will come on for a second then go back to sleep for 2 seconds randomly until either I blindly enter my password or unplug/plug the Thunderbolt connected monitor. Unplug/plugging the HDMI connected monitor does not seem to make a difference. Sometimes I need to unplug both and open the lid of the computer but that is only ever 1/10 times.

It never just wakes up correctly anymore. :-(

Eric Root

Level 10

684,045 points

Nov 30, 2016 4:42 PM in response to idano

You might want to consider starting a new discussion. Since this one is marked solved, less people are likely to look at it. A new post would be much more visible. You can link to this one. Post in the Sierra community.

External monitor no longer wakes from sleep (10.11.2 update)