MBP not waking up when an ext monitor is plugged in

Discussion in 'Mac OS X Lion (10.7)' started by mcb001982, Aug 29, 2012.

  1. mcb001982 macrumors regular

    May 27, 2008
    Manhattan NY
    I posted this in the MBP section but maybe this would be a better place to ask this question...

    I'm running Lion on my wife's 13" MBP and when ever she tries to wake the computer back up after closing the lid with an external monitor plugged in it will not wake. This is an issue since she's a teacher and shows power points all day. If you let the computer go to sleep with the lid open it wakes back up fine, the issue comes if you close the lid and they re-open it while connected.

    Specs on the machine if that makes a difference is a 2.4 c2d, 4gb of ram, and a 250gb drive.
  2. Musicsoul78 macrumors regular


    Aug 24, 2012
    The only time I have seen this model fail to work reliably is when there was a problem with the AC power (and it then was continually, but momentarily on battery and sleep is the correct answer) or when the lid isn't securely closed (a drop has bent things inside, or the lid doesn't close firmly, or the stand allows the lid to wiggle open/closed a touch.

    Have you poked around a bit to see if any of the things can be isolated (lid movement, power supply, connecting a USB device just to avoid a bluetooth drop from making it think it should sleep now).

    You don't need these changes permanently, but just to isolate why it might work sometimes and not another. If it fails all the time, you might need it serviced since Lion has worked out most of the sleep/wake screen issues associated with clamshell mode. (and there sure were a lot on 10.6 when we didn't know the VRAM was being allocated, but not reallocated on lid opening events as described in the support article you mentioned)
  3. mcb001982 thread starter macrumors regular

    May 27, 2008
    Manhattan NY

    This may be power related since we do have an intermittent issue with the computer not charging all the time. You can plug it in and it will stop charging on its own until you unplug/plug back in the charger.

    I did bring in the computer for the charging issue but since it only happens every now and then, the genius was not able to help me at that time with it.

    I will try the other things too you mentioned so I can try and isolate the cause, thanks.
  4. peixesloucos macrumors member


    Dec 1, 2012
    I am observing an issue slightly different than this.
    My MBP (Late-2011) is waking up slower when connected to LG external monitor. It is connected via HDMI cable (adapter).
    Do you know if there can be some settings to make the response of the monitor faster?

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