Windows 10: 2nd Display becomes primary when main monitor is switched off


  1. Posts : 6
    Win 10 Pro x64
       23 Jul 2017 #1

    2nd Display becomes primary when main monitor is switched off


    Hi,

    I have the following problem for a few weeks now:

    I have a "main" monitor attached to DVI and a beamer attached to HDMI of my GTX-960 graphics card. The monitor is set to primary display.

    For watching movies, I usually switch off the monitor, leaving only the beamer turned on. For a few weeks now, the beamer automatically becomes primary display when I turn off the monitor. It did not do this before. This behavior is very annoying, because it brings a black screen for a few seconds whenever I switch on/off the monitor, which I sometimes do while a movie is running. In addition KODI sometimes crashes in this moment and PowerDVD stops playing the movie.

    The only thing I have changed at that time was that I manually changed the beamer to primary for watching a 3D blu-ray, but I changed it back when the movie was finished.

    Does somebody have an idea about what causes this behavior and - more importantly - how I can stop this, i.e., keep the monitor beeing the primary display even when it is turned off?

    Thanks for all ideas!
    ai5g
      My ComputerSystem Spec

  2.    23 Jul 2017 #2

    ai5g said: View Post
    Hi,

    I have the following problem for a few weeks now:

    I have a "main" monitor attached to DVI and a beamer attached to HDMI of my GTX-960 graphics card. The monitor is set to primary display.

    For watching movies, I usually switch off the monitor, leaving only the beamer turned on. For a few weeks now, the beamer automatically becomes primary display when I turn off the monitor. It did not do this before. This behavior is very annoying, because it brings a black screen for a few seconds whenever I switch on/off the monitor, which I sometimes do while a movie is running. In addition KODI sometimes crashes in this moment and PowerDVD stops playing the movie.

    The only thing I have changed at that time was that I manually changed the beamer to primary for watching a 3D blu-ray, but I changed it back when the movie was finished.

    Does somebody have an idea about what causes this behavior and - more importantly - how I can stop this, i.e., keep the monitor beeing the primary display even when it is turned off?

    Thanks for all ideas!
    ai5g
    Hi @ai5g ,
    Welcome to tenforums! :)
    Are you using the WinKey+P to modify monitor projection or, are you simply turning the monitor off with the physical power button?
      My ComputerSystem Spec


  3. Posts : 6
    Win 10 Pro x64
    Thread Starter
       25 Jul 2017 #3

    The latter, I turn it off with the power button.
      My ComputerSystem Spec


  4. Posts : 6
    Win 10 Pro x64
    Thread Starter
       27 Jul 2017 #4

    Hmm, I was concerned that I am just too stupid... But now I feel better since even you guys here seem not to know the answer ;-)

    However, any ideas how I could approach the problem?
      My ComputerSystem Spec


  5. Posts : 6
    Win 10 Pro x64
    Thread Starter
       29 Jul 2017 #5

    I habe just noticed that the monitor disappears from the display settings once it is turned off. In contrast, the beamer remains in the settings even if it is turned off. Is there a way to stop the monitor from disappearing from the settings?
      My ComputerSystem Spec


  6. Posts : 6
    Win 10 Pro x64
    Thread Starter
       30 Jul 2017 #6

    Another observation:
    First oft all, thanks Edwin for the win+p idea, I didn't know this shortcut. If I use this to set "secondary only", this switches the PC monitor off, which is strange because the PC monitor is the main display (which should make the beamer secondary in my opinion).
      My ComputerSystem Spec

  7.    01 Aug 2017 #7

    "Second Screen only" means that only the secondary monitor is active (on), that will turn off the primary display. The Monitor set as the main display will turn off.
    "PC Screen Only" will reverse that, Primary will be On, Secondary off.
    "Extend" is both on.
    "Duplicate" Is both on but they mirror each other.
      My ComputerSystem Spec


  8. Posts : 6
    Win 10 Pro x64
    Thread Starter
       01 Aug 2017 #8

    Yes, but it behaves differently, as I said. However, I found a workaround. My graphics adaptor has two DVI-ports. Plugging the monitor into the other port prevents this problem.
      My ComputerSystem Spec


 

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