13 Replies Latest reply: May 23, 2014 1:17 AM by artur.hansson
antdude Level 1 Level 1 (10 points)

Hello.

 

How does one turn off/disable MacBook Pros (2008's 10.5.8 and 2012's 10.8.4)' screen/display when connected to an external display (e.g., a HDTV with its HDMI)?

 

Thank you in advance.

  • 1. Re: Turning off MacBook Pro's display when using an external display?
    Courcoul Level 6 Level 6 (11,470 points)

    Called Clamshell mode, but also requires an external keyboard and mouse:  http://support.apple.com/kb/HT3131

     

    Else the best you can do is turn off the backlighting with the screen brightness buttons F1/F2.

  • 2. Re: Turning off MacBook Pro's display when using an external display?
    antdude Level 1 Level 1 (10 points)

    Courcoul wrote:

     

    Called Clamshell mode, but also requires an external keyboard and mouse:  http://support.apple.com/kb/HT3131

     

    Else the best you can do is turn off the backlighting with the screen brightness buttons F1/F2.

    Thanks.

  • 3. Re: Turning off MacBook Pro's display when using an external display?
    vylla Level 1 Level 1 (0 points)

    i think turning down the screen backlight is not what really matters here, what is truly of interest when driving big external screens is to keep the workload on the gpu low inorder to prevent temperature rise in the laptop.

     

    as far as i observed, adding external displays increases the gpu workload significantly and with that comes temperature rise in the lapotop and increase in ventilator noise - and increased risk of component faillure due to high temperature in the laptop.

     

    simply try connecting two external 27" screens and open some flash video on them - and on the built.in screen. then run a temperature monitoring software and watch temos rise to very high levels.

     

    especially in maverick, due to its many additional background routines.

     

    so the question to which i have not found a reply anywhere so far, is how to switch the macbook pro`s built-in screen in order to avoid gpu cycles being wasted on that screen while working with big extrenal screen(s).

     

    hope that such a switch-off option exists or that apple comes up queickly with one.

     

    the gpu is by far the hottest running processor in the macbooks and keeping its running temperature low is crucial to component aging, ventilator noise etc.

     

    instructions for osx maverick welcome.

  • 4. Re: Turning off MacBook Pro's display when using an external display?
    ktam2 Level 1 Level 1 (0 points)

    I'd really like an answer to the issue that vylla brought up.

     

    I'd like to run with the Macbook Pro open to help with the cooling but when I've got a large second display attached to turn off the internal display and for it not to use GPU resources.

     

    Kevin

  • 5. Re: Turning off MacBook Pro's display when using an external display?
    kkwan77 Level 1 Level 1 (0 points)

    Discovered any other elegant solutions for this aside from using a magnet, the nvram command /(closing the lid on reboot) or turning down the display brightness? Prefer to keep the lid open for air circulation and opening and closing the lid every time during boot isn't ideal.

  • 6. Re: Turning off MacBook Pro's display when using an external display?
    stanfromdeu Level 1 Level 1 (0 points)

    I bought an rMBP not long ago and have been looking around for a solution for switching off the built-in screen while watching movies on a TV via HDMI.

    For me dimming the brightness via an automated applescript and then turning it back on using the same script solved it.

    I assigned a keyboard short cut to the script using the Scenario app from the AppStore. The full script is shown below. It additionally utilizes a self-made app called setKBBrightness to turn off keyboard backlight.

    I can post the source code of that too if anyone's interested.

     

    As far as I know dimming the screen doesn't actually turn it of. I use this with display mirroring on to avoid burn-in (due to having the same picture on the built-in screen for too long).

     

     

    property brightnessLevel : 0.75

    property currentLevel : 0

    property KeybBrightnessLevel : "930"

     

    ChangeBrightness(brightnessLevel) --Set this value between 0 and 1 to adjust brightness

     

    on ChangeBrightness(BrightnessValue)

     

              tell application "System Preferences"

      --activate

                        set current pane to pane "com.apple.preference.displays"

              end tell

              tell application "System Events" to tell process "System Preferences"

     

                        tell radio button "Display" of tab group 1 of window "Built-in Retina Display" to if value is 0 then

                                  repeat until value is 1

      click

                                  end repeat

                        end if

     

                        set currentLevel to value of slider 1 of group 1 of tab group 1 of window "Built-in Retina Display"

      --display dialog currentLevel

                        if currentLevel is 0 then

                                  tell slider 1 of group 1 of tab group 1 of window "Built-in Retina Display" to set value to BrightnessValue

                        else

                                  tell slider 1 of group 1 of tab group 1 of window "Built-in Retina Display" to set value to 0

     

                        end if

              end tell

     

      --switching auto keyboard backlight on-off

              tell application "System Preferences"

      --activate

                        set current pane to pane "com.apple.preference.keyboard"

              end tell

     

              tell application "System Events" to tell process "System Preferences"

     

                        if currentLevel is 0 then

      --switching on "Adjust keboard brightness in low light", that automatically gets the Keyb. backlight back on

                                  if value of checkbox "Adjust keyboard brightness in low light" of tab group 1 of window "Keyboard" is 0 then

                                            click checkbox "Adjust keyboard brightness in low light" of tab group 1 of window "Keyboard"

                                  end if

     

                        else

                                  if value of checkbox "Adjust keyboard brightness in low light" of tab group 1 of window "Keyboard" is 1 then

                                            click checkbox "Adjust keyboard brightness in low light" of tab group 1 of window "Keyboard"

                                  end if

      --switching off keyboard backlight

                                  delay 0.5

                                  do shell script "~/Documents/for_scripts/setKBBrightness 0"

                        end if

              end tell

     

     

              tell application "System Preferences" to quit

              if currentLevel is not 0 then tell application "System Events" to key code 124 using control down

    end ChangeBrightness

  • 7. Re: Turning off MacBook Pro's display when using an external display?
    kkwan77 Level 1 Level 1 (0 points)

    Right, Apple really needs to include an option to turn off the MacBookPro screen. I have no clue why this isn't offered, unless they want the unit to overheat thus pay out of the wazooo for repairs which is pretty shady business practice in itself. Otherwise I can't think of any other reason why they do not offer this option.

  • 8. Re: Turning off MacBook Pro's display when using an external display?
    William Kucharski Level 6 Level 6 (14,705 points)

    Don't close the lid all the way, just until the display shuts off.

     

    Usually this leaves the front of the lid open a good 2" or so for ventilation.

     

    However the MacBook Pro is designed to quite happily run all day in lid completely closed clamshell mode, except for the fact you wouldn't hear the built-in speakers well.

  • 9. Re: Turning off MacBook Pro's display when using an external display?
    kkwan77 Level 1 Level 1 (0 points)

    Right, well I use the internal speakers and prefer the air flow of it being open. They need to supply the option to turn this off with the shell open it's one of the most basic options, there's no need to reinvent the wheel here. Therefore people actually have a choice to run it open or closed.

  • 10. Re: Turning off MacBook Pro's display when using an external display?
    wlee777 Level 1 Level 1 (0 points)

    I recently upgraded from 10.6 to 10.9 and I couldn't find a way to shutoff the internal display while connected to an external display with the lid fully "open".   This helps cool down the laptop a bit with better heat dissipation.

     

    Running sudo nvram boot-args="iog=0x0"  did not do the trick for me. Any other ideas I could try?

     

    Will Apple provide a software option to turn off the internal display in this configuration in future releases?

  • 11. Re: Turning off MacBook Pro's display when using an external display?
    kkwan77 Level 1 Level 1 (0 points)

    Once you put those settings in you have to close the lid when you reboot or start up the computer.  Once the login screen appears you can reopen it and the screen is off. Timing is everything. Reboot/startup immediately close the lid before the screen turns on,  once the login screen appears you're good to open the lid.

  • 12. Re: Turning off MacBook Pro's display when using an external display?
    wlee777 Level 1 Level 1 (0 points)

    Thanks kkwan77,  this works for me - awesome!

  • 13. Re: Turning off MacBook Pro's display when using an external display?
    artur.hansson Level 1 Level 1 (0 points)

    What I've been doing in OS 10.9.2 with my MBA and Thunderbolt Display is to:

     

    1. have a hotcorner to turn of all screens or just press the shut down button that these days work like on the iPhone.
    2. then close the lid of your MB
    3. count to three
    4. open the lid
    5. VOILA - just the ThunderBolt starts up and I can still use the keyboard and touchpad.

     

    BUT! Since today with 10.9.3 - this bug has been fixed

     

    Apple - please insert an option to turn of the MacBook display. This helps me personally when watching movies and using iPhoto and iMovie making photobooks or videos.