How to turn off iMac screen but leave secondary screen on?

Discussion in 'iMac' started by Broric, Dec 21, 2009.

  1. Broric macrumors regular

    Oct 1, 2009
    I'm sure this should be simple but I can't figure it out.

    I have my iMac connected to my TV and am using Plex to watch stuff on the TV.

    What I'd like to do is turn my imac screen off without turning off the second monitor output (i.e. tv) as the imac screen is a bit bright/distracting (even on lowest brightness) when watching in the dark.

    Anyone know how to do this?
  2. tsugaru macrumors 6502

    Feb 9, 2003
    Does Ctrl + Shift + Eject work fine? Or does it blank both displays?
  3. opera57 macrumors 6502

    Feb 15, 2009
    I would also like to know how to do this. I think control + shift + eject turns both displays off :(
    When i'm running in Windows I can use the nVidia control panel to turn off the main monitor and just choose to use the external display, but in OS X I cannot find the option anywhere. So it is possible, its just a software issue.
  4. bellang macrumors member

    Jun 22, 2005
    I've been looking around for a solution to this as well, alongside the opposite (to stop using an externally connected display when its plugged in) and so far haven't found a solution.

    Only way so far is to use windows, which isn't the most ideal setup to dual boot!
  5. bellang macrumors member

    Jun 22, 2005
    Found this, but havent tried it yet, as at work on a PC;

    You can disable or deactivate a monitor without having to physically unplug it, allowing you to use a laptop in clamshell mode with external monitor, keyboard and mouse

  6. Broric thread starter macrumors regular

    Oct 1, 2009
    Still not found a solution, surely there's a simple one out there?
  7. gospel9 macrumors regular

    Sep 20, 2008
  8. OGDaniel macrumors 6502a


    Dec 24, 2009
    This really does seem like a problem with an easy solution. I don't think there is one though :(
  9. doug in albq Suspended

    doug in albq

    Oct 12, 2007
    There is no easy way to make this happen...

    It was one of the many reasons I sold my iMac and went with a MacBook / external display setup.
  10. stroked Suspended


    May 3, 2010
    I guess there still isn't a solution to this?
  11. RedReplicant macrumors 6502a

    Mar 31, 2010
    There is an option to blank the second screen in the PLEX options.
  12. Demosthenes X macrumors 68000

    Demosthenes X

    Oct 21, 2008
    What are you using to watch video with? VLC has an option to blank the other screen during playback...
  13. stroked Suspended


    May 3, 2010
    I'm watching Netflix on my TV with my imac. Thanks for the tip on VLC, I use that app for watching DVDs

    PLEX will not help with Netflix either. That seems to work only with media on your computer.
  14. kaw macrumors newbie

    May 25, 2011
    SwitchResX handles this...

    Just wanted to verify that SwitchResX does work on my iMac. I'm not sure why that suggestion was disregarded. It's not free, but $19 (as of today) isn't much to fix this shortcoming with iMacs. It took five minutes to setup proper hotkeys and whatnot.

    There's a free trial (which I just tested with). Plan on buying now...
  15. Stetrain macrumors 68040

    Feb 6, 2009
    Does the screen brightness on the iMac not go to 0? On my Macbook I can turn the screen brightness down until the screen turns off.
  16. pumpkinwhite macrumors member

    Sep 3, 2006
    Ran into this thread, and though it's old, thought i'll chime in.
    I use a free utility called 'Shades'

    It lets you decrease the brightness of the main or any attached screen to zero. However, keep in mind that the screen does not technically turn 'off'. When I turn the imac screen brightness to zero with this utility, the screen goes black, but i can still see the faint glow of the backlight being on. It's not distracting, but thought you should know. Also, be aware that while testing it, if you turn it to zero, and lose the cursor position, you won't be able to see anything on the screen. You have to hit the 'emergency off' (Alt+esc) to get it back.

    It works great, though I think it is no longer in active development. Not sure if it works in Lion. Works on my snow leopard imac though.

    On a side note - Good solution when using logmein or any such remote login utility. Trying to find a remote login utility that lets me blank the imac screen, when logging in from windows, but cannot find any. But that is another thread :).
  17. grovertdog, Jan 3, 2013
    Last edited: Jan 3, 2013

    grovertdog macrumors regular

    Sep 14, 2006
    It works GREAT in Mountain Lion! THANK YOU, THANK YOU, THANK YOU!!! My theatre room is DARK again!
  18. cynics macrumors G4

    Jan 8, 2012
    Sorry to resurrect this thread but has anyone found any better solutions then the ones presented above?

    SwitchResX is relatively expensive for what I need and does too much (I couldn't figure it out in 5 minutes and quickly lost interest). Shades defeats the purpose of what I'm trying to accomplish. I want the display to be off not displaying a black screen wasting power in my office while its streaming content to me in the living room.

    It seems MacBooks can do this and it can be done through software in Windows on an iMac but not in OSX?

    Just seems like a waste to run a display in a room I'm not in. I would think Apple would have accounted for such use when mirroring a display to an AppleTV.

    Thanks in advance if anyone can help me out.
  19. Dreadnought macrumors 68020


    Jul 22, 2002
    Almere, The Netherlands
    When using airplay to an Atv the iMac's screen goes into sleepmode, according to your powersavings settings, or make an interactive corner to put the iMac's screen to sleep. Hope this helps.
  20. cynics macrumors G4

    Jan 8, 2012
    Anytime the iMac display sleeps the mirrored display sleeps too, well it goes black. Plus it will never sleep if I'm using a keyboard/mouse or watching a video etc. An interactive corner is just a short cut to sleep, the secondary display still goes black (its mirroring sleep) when I do that.
  21. Dreadnought macrumors 68020


    Jul 22, 2002
    Almere, The Netherlands
    What you're wanting to do, mirroring the screen and put the screen of the iMac into sleepmode while having another screen not into sleep, can't be done AFAIK. Therefore I suggested AirPlay as you talked about streaming content. With AirPlay this is possible and it works.
  22. mypol macrumors newbie

    Sep 7, 2014
    Use a black jpeg - turn off mirror mode

    Here is a work around I just tried and it worked. I have a 2014 iMac with a Sony HDTV connected. I'm converting the thunderbolt out of the iMac to HDMI going into the TV. No Apple TV or Airplay involved.

    Go into System Prefs and turn off Mirroring. You can open up the black jpeg (attached) on the imac in the Preview app and under the VIEW menu you can set it to Enter Full Screen on the iMac screen. Then you'll be watching Netflix or whatever on your TV.

    It would be much better if Apple just had a button to make the screen go to sleep since you are still powering the monitor wastefully.

    Attached Files:

  23. pmt24mac macrumors newbie

    Nov 5, 2014
    Hamilton, On, Canada
    External Monitor on iMAC

    Install the DisableMonitor app from:

    This allows you to enable/disable the two monitors independently as well as set their resolution
  24. futuremike1 macrumors newbie

    Feb 17, 2015
    I found the easiest solution

    Download a black picture on google Images. Make it full screen on your iMac display and lower the brightness all the way. Drag whatever you want to your external display and Enjoy.

    I made this account just to answer this question for anyone who's wondering for the future.
  25. orbulet macrumors newbie

    Nov 11, 2015
    YES. This was simple, free and worked perfectly. Thanks!

Share This Page