Apple Event: May 7th at 7 am PT
I'm using 2 imac 27' and one is simply used as an external display. When I wake up the computer from sleep, it works on the main monitor, however the external display still has a black screen. I have to unplug the external monitor to get it to wake up. Is there anyway to fix this?
iMac
I do own an Apple CinemaDisplay 23" Alu connected to mini displayport with a DVI / mini displayport adapter, on a 15" retina mbp 2013, and have the exact same problem.
What is weird is that I have another mbp, 13" 2011, with the exact same setup, and the problem never occured.
So it may be linked to retina actually ?
What's sad (and maybe a shame), is that Apple is not abble to correct this problem with its own hardware setup...
My external Samsung monitor displays a message saying the best resolution is 1920 x 1080.
When I open the dispays control panel, none of the resolution options come even close to that. If I select "Best for display," the system seems to select 800 x 600 and then enlarge everything to fill the external monitor.
Holding down the OPTION key while I click the SCALED radio button, additional resolutions appear - including the 1920 x 1980 that Samsung suggests.
As with the other posts in this thread, everything is great until the monitors go to sleep. The only one of the solutions I've read hear that worked for me was unplugging the monitor cable and plugging it back in.
It appears, however, that if I open the displays control panel, click the "GATHER WINDOWS" button on my Mac's screen, then click the "Best for display" button in the Samsung monitor's control panel, the Samsung monitor wakes, set at 800 x 600. Holding down the OPTION key and clicking the SCALED radio button allows me to return the Samsung monitor to 1920 x 1080 resolution.
I've tried this only twice, but if it continues to work I'll be trying to set up a script in Applescript or QuickKeys to automate the process.
This is an external fix from a non technician. For most situations un-plugging and re-plugging one of the connections brings the monitor back. In my case I bought a multi-USB port that has on/off buttons for each USB port. Now instead of pulling out the USB, I just turn the button off and on again.
And it keeps happening in Sierra. Though I didn't face this with El Capitan, or Maverics.
Yes, I still see it occasionally after all these years. Unplugging the Thunderbolt-to-DVI converter, then replugging (a few times) seems to work for me.
External Monitor Won't Wake Up from Sleep
