joshfromcedar rapids

Q: Apple Cinema Display (20-inch DVI 2005) not working after 10.10.3 update

I have an Apple Cinema Display (20-inch DVI 2005) that isn't working after installing the 10.10.3 update. The screen is just blank, and the power light just blinks a few times every 30 seconds or so. I use this as a second monitor with my iMac (27-inch, Late 2012). Any way to fix this? Thanks!

iMac, OS X Yosemite (10.10.3)

Posted on Apr 20, 2015 7:36 AM

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Q: Apple Cinema Display (20-inch DVI 2005) not working after 10.10.3 update

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  • by sterling r,

    sterling r sterling r Apr 23, 2015 7:53 AM in response to joshfromcedar rapids
    Community Specialists
    Apr 23, 2015 7:53 AM in response to joshfromcedar rapids

    Howdy Josh,

     

    It sounds like your LCD Cinema Display's power light is flashing 3 times quickly a couple times a minute. According to the following article it sounds like you should reset your PRAM:

     

    Apple LCD displays: Power light flashes

     

             
    PatternMeaning
    short, short, shortThe display is detecting wrong video format or an unsupported resolution.
    Verify that your equipment is compatible and restart the computer. If the issue continues, reset the PRAM

     

    If it is not three short blinks, refer to the article for other troubleshooting for that. Here is also the updated PRAM reset article for Yosemite:

     

    OS X Yosemite: Reset your computer’s PRAM

     

    Thank you for using Apple Support Communities.

    Cheers,

    Sterling

  • by joshfromcedar rapids,

    joshfromcedar rapids joshfromcedar rapids Apr 23, 2015 2:00 PM in response to sterling r
    Level 1 (0 points)
    Apr 23, 2015 2:00 PM in response to sterling r

    Thanks for the suggestion, but sadly it didn't take care of the problem. I tried it 3 times. After watching the blinking light closer, the pattern is short, long, short. And according to your link that just means I should make sure I'm using the correct power adaptor, which I am. It's still the same factory power adaptor I've been using with it for 7 years or so. This started right after I did that OS update, so I feel like it has to have something to do with that. Any other thoughts?

     

    Thanks!

  • by just the new guy,

    just the new guy just the new guy Apr 24, 2015 2:22 PM in response to joshfromcedar rapids
    Level 1 (0 points)
    Apr 24, 2015 2:22 PM in response to joshfromcedar rapids

    Not sure this is for everyone, but this might be a workaround.  I had the same problem, but this worked:

     

    after a restart, I waited until it would have been the password screen

    entered my password as usual (blind with no monitor)

    used the command+option+power button hotkey to put the system to sleep

    counted to 20

    clicked the space bar, and the monitor started working again. 

     

    Could fail on a restart, but it's working now

  • by sterling r,

    sterling r sterling r Apr 26, 2015 8:47 AM in response to joshfromcedar rapids
    Community Specialists
    Apr 26, 2015 8:47 AM in response to joshfromcedar rapids

    Thank you for the update!

     

    Next I would recommend the Reset the System section of the following article for additional troubleshooting:

     

    Apple computers: Troubleshooting issues with video on internal or external displays

    Reset the system

    You can reset the Mac's parameter RAM and SMC.

     

    Reset the resolution

    Start by resetting the Mac's parameter RAM. If the display does not come up, was previously set to an unsupported resolution, and still results in no video:

    1. Start up in Safe Mode.
    2. From the Apple () menu, choose System Preferences.
    3. Choose Displays from the View menu to open the preferences pane.
    4. Select any resolution and refresh rate that your display supports.
    5. Restart your computer.

    I would reset the SMC and the PRAM together, in that order one more time, then do the Safe Boot if needed.