External monitor doesn't wake up when macbook does

Discussion in 'MacBook Pro' started by christarp, Feb 1, 2014.

  1. christarp macrumors 6502


    Oct 29, 2013
    Hey guys, a small issue I've been having with my late 2013 rMBP now. Every time I wake the computer up from sleep the external monitor stays sleeping, all the windows get rearranged into one screen and it doesn't seem to detect it. I have to unplug and plug the HDMI cable back in again to get it to detect the monitor and re-arrange my windows the way I had them again, any solution to this other than taking out the HDMI cable and putting it back in like I have been doing?
  2. vexingv macrumors newbie

    Dec 15, 2008
    do you have multiple inputs for your monitor? i had a similar issue with my Acer monitor that has both DVI and HDMI inputs. I was try to use both simultaneous to switch between a desktop pc and a clamshelled rmbp (think poor man's KVM), but it didnt quite work. now i only connect via hdmi.

    i suspect your issue is probably related to a bad passage of EDID that signifies that your computer is now on/awake. maybe try a different cable? have you tried powering on/off the monitor while connected?
  3. christarp thread starter macrumors 6502


    Oct 29, 2013
    I do have multiple inputs to my monitor actually, an HDMI that I use to connect to my macbook, and a DVI cable connected to a PC. I've tried power cycling the monitor but when it's not recognized the only way to get picture back is to unplug the cable from the macbook itself. Somehow doing that reinitializes the whole thing and the picture comes back.

    Multiple cables have been tried and they both do it, but only sometimes. Sometimes it's able to wake from sleep just fine, and sometimes the picture is gone until unplugging HDMI and plugging it back in. Not really sure how to approach the problem.
  4. dalupus macrumors regular

    Jul 19, 2011
    I'm having the exact same issue with my rMBP 2012.
    Has worked perfectly since the day I bought it but I installed mavericks 2 days ago and have had 2 occurrences of this since.

    Seems to be a bug in mavericks.

    I am using a thunderbolt to dvi cable. Only way to get it to wake up is reconnect the cable, which as you mentioned, is extremely annoying because all of my windows get rearranged.

    Also in my case the computer isn't even going to sleep. just the displays.
  5. dalupus macrumors regular

    Jul 19, 2011
    interestingly I just left it for a bit after I woke my computer back up and sure enough about 30 seconds later the monitor finally woke up.
  6. dalupus macrumors regular

    Jul 19, 2011
    well scratch that. Today the monitor wouldn't wake up.
  7. dalupus macrumors regular

    Jul 19, 2011
    the easiest way I have found to wake the monitor up is to simply hit the power button(on the mac) for a second to put it to sleep then hit it again to wake up.

    Takes just a few seconds and is much less painful than having to rearrange all of my windows.

    It is pretty absurd that such a basic feature in mavericks isn't working correctly.

    I have become increasingly annoyed by small OSX bugs that they seemingly just ignore. I really wish they would slow down the release cycle on OSX a bit and spend more time fixing bugs.

    One of the main reason people move to OSX is to have a more stable operating system. I am not so sure OSX is any better than Windows in that regard anymore.
  8. FJMBP2009 macrumors newbie

    Aug 17, 2014
    MacBook Pro External Monitor Does Not Wake Up - Solution

    I have a late 2009 MBP 2.8 Dual Core that I just upgraded to Mavericks. Not sure if Mavericks has anything to do with my external monitor going and staying black, but it is something that has obviously "changed" in my system environment recently so I am mentioning it.

    I stepped away from my MBP and when I returned it had gone to sleep. When I tried to wake it up my MBP screen woke up but only displayed a dark gradient gray and my Apple monitor was black/nothing. I rebooted the system, unplugged and replugged the (external) Apple monitor (mini HDMI) to the MBP, and changed graphics card/Energy configuration. My desktop returned on my MBP screen but the external monitor remained black. I plugged someone else's MacBook Pro into the monitor and the monitor still did not work. Nothing would get the external Apple monitor to work.

    Finally I unplugged the Apple monitor power cord, then plugged it back in and all is well. So unplugging the monitor power cord did the trick for me in this situation.
  9. MacSince92 macrumors newbie

    Nov 7, 2014
    External monitor doesn't wake up when macbook does SOLUTION

    I had this problem for a long time until, yesterday, I solved it on my mac mini. The problem is that there are 2 different places in the System Preferences where you can set the time fo the display to go to sleep, namely in "Desktop & Screen Saver" and in "Energy Saver". I can't remember what exactly were the times I had set previously but it generated a conflict. Now I have set the times to 15 minutes in "Desktop & Screen Saver" menu, and 1 hour in "Energy Saver" menu and the problem is gone.
  10. dalupus macrumors regular

    Jul 19, 2011
    mine is already set to 10 minutes and 1 hour respectively. I would give it a few days. I imagine your problem will return. It comes and goes for some reason.
  11. MacSince92 macrumors newbie

    Nov 7, 2014
    Hmm, I hope not but I will let you know in a few days.
  12. Mactaculious macrumors regular

    Oct 6, 2014
    I have this issue, it happens on startup occasionally and waking up form sleep. My other external monitor connected via the thunderbolt port/dvi-d has no issues. I tend to have to power off my monitor when I sleep the Macbook Pro or when I turn it off, to avoid having to unplug it/re-plug it back in.
  13. newtestleper macrumors 6502

    Jun 17, 2013
    I'm getting this problem for the first time with El Capitan beta 2. A quick fix is to go into Displays in System Preferences and press alt-option to toggle the "Gather Windows" button at bottom right to "Detect Displays". I had to click it twice to get my second monitor to turn on.
  14. emdub macrumors newbie


    Mar 23, 2005
    Sintra, Portugal
    Had this problem with El Capitan b2 too. The detect displays didn't work for me, but disconnecting the power chord on the monitor and reconnecting did. This is an 23" Apple Display connected through a thunderbolt to DVI converter. Anyway, another thing to try if having problems connecting an external display to El Capitan.
  15. yukyuklee macrumors 6502


    Jan 4, 2011
    Boston, MA
    I just press ESC key and have to wait about 15-20 seconds, yeah it gets annoying.
  16. GreeKatrina macrumors newbie


    Dec 19, 2017
    Austin, TX
    This works for me as well. Was having to unplug it and plug it back in before.
  17. macIsShit3000 macrumors newbie

    May 9, 2019
    Great! I have paid 3000$ to unplug/plug my monitor each time my mac goes to sleep or wait 20 secs when after pressing ESC!
    Really what the hell is this! This issue is apparently as old as the my grandfather and it's still around!
    Get your **** together Apple!

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16 February 1, 2014