mamlukman

Q: Display or computer not working--which??

I woke up this morning to a blank (black) Apple Cinema Display screen.  I thought it was asleep as usual, but it didn't respond. I turned off the computer and turned it back on. The screen flashed in a horizontal line and then went black. After that one flash, subsequent re-startings of the computer have done nothing to the screen.

 

I have a Apple Cinema Display and a MacPro computer, both c. 2011 or 2012. I bought them through Craigslist 2 1/2 years ago, and they have worked fine until today. The MacPro is running the latest El Capitan system.

 

I thought I would test the display with my Macbook--plugged in the display plug to my laptop. Nothing. It seems to see it in systems preferences because if you go to "displays" it says "LED cinema display". But is there something else I need to do to get the display to come to life?  Some mysterious command, or turn the laptop on and off??

 

Then I thought I would check the computer itself. When I turn it back on, there is the familiar `'ding" as it boots up, but that's it. I tried accessing it through wifi and my laptop, but when I go to "connect to server" the laptop doesn't see it. So I can't get to the computer.

 

So now I'm completely baffled--is the problem the display or the computer? Or both?  What do I do???

Posted on Jun 14, 2016 6:59 AM

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Q: Display or computer not working--which??

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  • by D.Cohen,

    D.Cohen D.Cohen Jun 14, 2016 7:01 AM in response to mamlukman
    Level 6 (8,424 points)
    Desktops
    Jun 14, 2016 7:01 AM in response to mamlukman

    Hi.

    Take a look at the steps suggested by Apple in this article:

    If your Mac won't turn on - Apple Support


    Try Safe Boot:


    - Shut down your Mac

    - Wait until your computer turns off and after that press the Power button

    - Right after you hear the startup tone, press and hold the Shift key

    - Release the Shift key when you see a grey Apple sign and the progress bar below this sign

    - After your Mac boots up, restart it as you usually do.


    If this doesn't help, follow the instructions below:


    - Shut down your Mac

    - Wait until your computer turns off and after that press the Power button

    - Right after you hear the startup tone, press and hold the Shift key

    - Release the Shift key when you see a grey Apple sign and the progress bar below this sign

    - Once you see Desktop, start a Disk Utility scan to detect and repair file system errors (don't forget to choose your main hard drive)

    - Click on Verify Disk and then, if asked to fix problems, on Repair Disk

    - After this, click on Verify Disk Permissions and then on Repair Disk Permissions

    - After the process is finished, shut down your Mac and turn it back on after about 30 seconds


    Apart from that, take a look at this Apple article and follow the instructions on Resetting NVRAM shown there: How to Reset NVRAM on your Mac - Apple Support


    Try resetting the System Management Controller: https://support.apple.com/en-us/HT201295


    Hope this helps!

  • by mamlukman,

    mamlukman mamlukman Jun 14, 2016 7:22 AM in response to D.Cohen
    Level 1 (5 points)
    Desktops
    Jun 14, 2016 7:22 AM in response to D.Cohen

    I actually read all that before my posting.  None of it applies, as far as I can see. It's not like I'm setting up a new system or messing with the controls or plugs--everything has been the same way for 2 1/2 years. Power is getting to both the computer (it has the "on" light and fan works) and the display (laptop can see it).

     

    Then why can't the display show the laptop screen?  And why doesn't wifi see the computer? 

  • by lllaass,

    lllaass lllaass Jun 14, 2016 7:24 AM in response to mamlukman
    Level 10 (188,724 points)
    Desktops
    Jun 14, 2016 7:24 AM in response to mamlukman

    Have you tried:

    Get help with video issues on external displays connected to your Mac - Apple Support

    What model MacBook and how was it connected to the monitor?

    What specific Cinema display?

     

    When a second compatible monitor is connected you shold see both in Display Perferences and a chck box of what to do with it. Mirror the existing screen or as an extended desktop.. The following applies to all later iOS version

    OS X Yosemite: Connect multiple displays to your Mac

  • by mamlukman,

    mamlukman mamlukman Jun 14, 2016 9:16 AM in response to mamlukman
    Level 1 (5 points)
    Desktops
    Jun 14, 2016 9:16 AM in response to mamlukman

    Problem is "solved"--I gave up trying to get the display to work on my laptop, so I plugged it back into the Mac Pro.  Magically, it turned right on.

     

    So that leaves me scratching my head over two things:

    1) Why didn't it work earlier?  No one had moved the computer…connections hadn't come loose. So why would plugging it in again "fix" it?

    2) Why wouldn't the display come up on the laptop?  (and no, I'm not about to tempt fate by unplugging the display and trying again with the laptop.

     

    Anyway, Thanks to those who responded, and if anyone can answer my two questions above, I'm all ears.