No second screen on battery power ?

Discussion in 'MacBook Pro' started by Foxile, Nov 16, 2010.

  1. Foxile macrumors regular

    Joined:
    Dec 27, 2007
    #1
    Am I right in assuming that my MBP will switch off power to the Mini Displayport, when running on batteries ?

    Well mine does, but want to make sure that's right ?
     
  2. spinnerlys Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #2
    My does run a second display while on battery - 17" MBP from 2009 with 9400M.

    If you still have warranty you should have Apple take a look at it.
     
  3. toxic macrumors 68000

    Joined:
    Nov 9, 2008
    #3
    it won't turn it off after unplugging, but it won't start if your MBP isn't plugged in to start with.
     
  4. spinnerlys Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #4
    Okay, I just tested it again and I run on battery, unplugged the monitor and plugged it back in and it took a bit longer (two to four and a half seconds) to actually recognise the monitor compared to when running the MBP on AC, but right now I run a second monitor while on battery.

    Btw, I use a MDP to VGA adapter, if that is worth anything.
     
  5. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
  6. henry999 macrumors newbie

    Joined:
    Oct 27, 2010
    #6
  7. Bernard SG, Nov 17, 2010
    Last edited: Nov 17, 2010

    Bernard SG macrumors 65816

    Bernard SG

    Joined:
    Jul 3, 2010
    #7
    It'll work on battery but will drain substantially more energy.
    I don't think it's normal that it switches off, but I haven't tried with 10.6.5 yet.
     
  8. Foxile thread starter macrumors regular

    Joined:
    Dec 27, 2007
    #8
    Sorry, GGJ is right. I am trying to use it in a closed clamshell setup, so I can run the battery down, while using it how I do, day-to-day.
     
  9. henry999 macrumors newbie

    Joined:
    Oct 27, 2010
    #9
    And we were supposed to know that ... how?

    The ol' rule still applies: the more information you provide, the better advice we can give.

    cheers,

    Henry
     
  10. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #10
    The OP got their answer. That's all that matters.
     
  11. Foxile thread starter macrumors regular

    Joined:
    Dec 27, 2007
    #11
    In all fairness, I would expect it to provide power to the Mini Displayport, when the lid is closed, otherwise you can't use any screen at all.

    I would have mentioned, if I'd thought it was pertinent.

    I was hoping is was a MD fault, as I'm getting crap HDMI performance
    ( http://forums.macrumors.com/showthread.php?t=1048660 )
    , which might have accounted for it.
     
  12. Fubar1977 macrumors 6502a

    Fubar1977

    Joined:
    Jul 30, 2010
    Location:
    North Yorkshire, UK
    #12
    I use my 15" i5 on battery most nights running video on a 42" HDTV using mini displayport to HDMI and it always works fine.
    It does seem to use a lot more power though (understandably I suppose).
     

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