fiona.mac

Q: iMac 27" Black Screen?

For 6 long and painful weeks, my 27" iMac (10.7.5) has intermittently turned itself to sleep mode (black screen). It's driving me up the wall and sent my productivity through the floor. You'll be in the middle of something and whammo, black screen. I have to push the power button to get the screen to work again. It doesn't respond to keyboard or mouse.

 

The screen turns black when you're on the Internet, playing quicktime files, using Microsoft office, so it happens across different applications... it happens on my account, my daughter's account, the guest account. It is indiscriminate, it just does it whenever it feels like it, but not all the time. If it shuts down video, the audio still plays, there is just a black screen with no picture to watch.

 

The computer is 8 months old and I have Apple Protection as well, so that's not the problem, but I see other people have experienced a similar issue and I'm up for suggestions as to what you think might be causing the problem.

 

So far, these are the fixes that have been done and NOT fixed the problem:

 

  • OSX has been reinstalled twice
  • The logic Board has been replaced
  • RAM has been replaced
  • The graphics card has been replaced

 

The tech is coming back out Monday to replace the power supply and the screen. If this doesn't work I'm told I'll be reissued with a new machine.

 

So any other suggestions out there? Is it possessed by a ghost? Cursed? Just should be declared a lemon?

iMac, Mac OS X (10.7.5), Bought July 2012, Built mid 2011

Posted on May 2, 2013 9:56 PM

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Q: iMac 27" Black Screen?

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  • by MuratCalis,

    MuratCalis MuratCalis Apr 7, 2015 4:14 PM in response to jhnmorely
    Level 1 (0 points)
    Apr 7, 2015 4:14 PM in response to jhnmorely

    You can add me to the list too.. Unfortunately.

     

    10- 15 minutes ago black screen with a cursor fail had happened to my computer.

    But different from other users, after restart from button my computer started working...

    But after a quick search I stated that is a common and urgent matter to all apple users.

     

    And I think not for apple comp.. Sadly.

    After selling most expensive hardware on the market around the world, they have to

    solve our problems so as their products problems rapidly. 2013 to 2015 there is a

    great deal of time to diagonise the problem and fix it both software and hardware

    part of product.

     

    I will check it regularly from now on.

     

    (Sorry for my bad english.)

  • by Eprom,

    Eprom Eprom Apr 8, 2015 6:16 AM in response to Eprom
    Level 1 (0 points)
    Apr 8, 2015 6:16 AM in response to Eprom

    UPDATE

    Even though my iMac was bought in 2011, Apple was so kind to replace the complete display + backlight and everything works fine again.

  • by Manuarmata,

    Manuarmata Manuarmata May 2, 2015 5:23 AM in response to Eprom
    Level 1 (0 points)
    May 2, 2015 5:23 AM in response to Eprom

    Mine stayed good for 7 months after setting the monitor on FULL brightness and not one block less. unfotunatly today it occurred again one time.

    Im not sure how it wil develop now but setting it on full brightness was at least good for a very descent time.

  • by Guy Burns,

    Guy Burns Guy Burns May 2, 2015 5:29 PM in response to Manuarmata
    Level 2 (349 points)
    Applications
    May 2, 2015 5:29 PM in response to Manuarmata

    Loose connection somewhere is my best guess. A friend asked me to look into his problem, so I went to have a look. Bad – after the first hour problem free, it occurred every few minutes and became unusable. Took it home with me, and the problem disappeared. Returned it to him, and it was okay for a few months, then got so bad he put the computer in the car to take to Apple. Was unable to deliver that day, so used it that night. No problems. Good for another several weeks. Then got bad again.

     

    How else to explain that moving the computer can fix the problem, other than a loose connection?

     

    Also, mine has never displayed the problem, but maybe once in 20 turn-ons I can hear an arcing noise for half a second. Don't know where it's coming from (could be the mains cable). The screen's never gone black but I'm thinking: there's a loose connection somewhere in my machine. I wonder if it's to do with the black screen problem?

  • by Expedition Nentikobe,

    Expedition Nentikobe Expedition Nentikobe May 10, 2015 5:43 AM in response to fiona.mac
    Level 1 (0 points)
    May 10, 2015 5:43 AM in response to fiona.mac

    Try Preferences Bluetooth Advanced and Uncheck "Allow Bluetooth devices to wake this computer "

  • by cyrano7,

    cyrano7 cyrano7 Jun 17, 2015 11:16 PM in response to stbodie
    Level 1 (1 points)
    Jun 17, 2015 11:16 PM in response to stbodie

    I tried this and it has worked for a few days. And counting

     

    For want of a better metaphor, it seems that the innards of the computer have only a tenuous grasp on the monitor. So, I set the desktop to change images every minute, and the screen saver to slow slides. Logic might say that this allows the brains to exert continuous control over the monitor and thus prevent it from lapsing.

     

    Anyway, that is my logic, and my latest attempt to keep the monitor from going black.

  • by cdroot,

    cdroot cdroot Jun 18, 2015 11:29 AM in response to cyrano7
    Level 1 (0 points)
    Jun 18, 2015 11:29 AM in response to cyrano7

    OK I think I fixed it! Go to the display options, and turn of auto dimming. I think it's that dimming sensor that is faulty from being used over the years. In most cases, the computer is still on after the screen turns black, so that means just the computer screen is off.

     

    You just have to manually control the brightness with the keyboard now.

  • by cyrano7,

    cyrano7 cyrano7 Jun 18, 2015 1:14 PM in response to cdroot
    Level 1 (1 points)
    Jun 18, 2015 1:14 PM in response to cdroot

    A) thanks.

    B) could you be real specific (but simple) about where to find the "auto dimming"? I have a late 2009 27 iMac, using Mavericks, and I don's see it when I open up displays.

     

    Thanks.

  • by cdroot,

    cdroot cdroot Jun 18, 2015 4:04 PM in response to cyrano7
    Level 1 (0 points)
    Jun 18, 2015 4:04 PM in response to cyrano7

    go to 'system preferences', 'Displays', and uncheck 'automatically adjust display brightness'. Unless you don't have this functionality on your mac?

  • by cyrano7,

    cyrano7 cyrano7 Jun 18, 2015 4:25 PM in response to cdroot
    Level 1 (1 points)
    Jun 18, 2015 4:25 PM in response to cdroot

    I don't appear to have that functionality.  I just have basic choices of DISPLAY, COLOR, RESOLUTION, SCALED, and SHOW MIRRORING OPTIONS.

     

    I have an early 2009 24 inch on Mavericks, and a late 2009 27 inch on Yosemite. Neither one shows that functionality.

    (the 27 is the one with the black screen problem)

     

    ?

  • by Billymick,

    Billymick Billymick Jul 19, 2015 1:17 PM in response to Guy Burns
    Level 1 (0 points)
    Jul 19, 2015 1:17 PM in response to Guy Burns

    I am a new black screen sufferer. Let me share the detail briefly. 27" iMac vintage 2011. Dragged it in to the local store a few weeks ago. They could not replicate fault despite running tests and having the machine on test for 18 hours so they handed it back. It was no better when I set it up again and I tried many of the suggestions on this thread. It got to a point when it was going black on start up before reaching the login screen. Dragged it back to the store and this time the fault repeated itself on the service counter so they said they would replace the video card (quoting UK consumer law but in actual fact Apple had already issued a notice on this particular video card in this manufacturing batch of machine). I got a call from the store asking if it was OK to clear down the HD and reload the operating system suggesting that installing a new video card had not cleared the black screen fault. I ok'ed this and picked the unit up last week. After 2 hours of use the fault has returned. I plan to couple the unit up to a second monitor to confirm it is just the video component dropping out (which seems to be confirmed by other people commenting on this issue) prior to returning to the Apple Store for the third (and last) time. Personally I think it disgraceful that a business this big with as much income as they generate cannot fix this problem effectively.

  • by Billymick,

    Billymick Billymick Jul 20, 2015 12:09 PM in response to Billymick
    Level 1 (0 points)
    Jul 20, 2015 12:09 PM in response to Billymick

    Here is an update to yesterday's post. Finished last night restarting the iMac after the black screen kept reappearing seconds after clearing via Cmd-Alt-Eject but couldn't get to the login screen before going black again. 8 hours later it booted normally. Connected to a second monitor and waited for the first black screen which came about 1/2 hour later but the second monitor stayed on playing YouTube. Downloaded Owly but the black screens continued periodically. Dropped the main screen brightness to 2 bars and black screens stopped appearing over a couple of hours. Added one bar to the screen intensity and got an immediate black screen. Went back to 2 bars and again ran without blackouts for a couple of hours. Decided to eliminate the wired keyboard as a cause so disconnected and used the mouse on preferences to increase intensity slightly and got an immediate black screen so recoupled keyboard and went back to 2 bars and again stability returned. Temperature monitoring shows GPU diode at 149 F, GPU heat sink at 138 F and CPU Core at 99 F and casing is warm but not boiling hot. The graphics card is new from last week and based on other posts the temperatures at not high. After several hours of playing YouTube videos I seem to have stability at 2 bars intensity and immediate black screen if I go over 2 bars. Anyone got a concrete cause for this? My next step is to upgrade from Mavericks to Yosemite after which it is either back to Apple store or live with 2 bar screen brightness until it goes phut completely.

  • by rkaufmann87,

    rkaufmann87 rkaufmann87 Jul 20, 2015 12:13 PM in response to Billymick
    Level 9 (58,598 points)
    Photos for Mac
    Jul 20, 2015 12:13 PM in response to Billymick

    Billymick wrote:

     

    Here is an update to yesterday's post. Finished last night restarting the iMac after the black screen kept reappearing seconds after clearing via Cmd-Alt-Eject but couldn't get to the login screen before going black again. 8 hours later it booted normally. Connected to a second monitor and waited for the first black screen which came about 1/2 hour later but the second monitor stayed on playing YouTube. Downloaded Owly but the black screens continued periodically. Dropped the main screen brightness to 2 bars and black screens stopped appearing over a couple of hours. Added one bar to the screen intensity and got an immediate black screen. Went back to 2 bars and again ran without blackouts for a couple of hours. Decided to eliminate the wired keyboard as a cause so disconnected and used the mouse on preferences to increase intensity slightly and got an immediate black screen so recoupled keyboard and went back to 2 bars and again stability returned. Temperature monitoring shows GPU diode at 149 F, GPU heat sink at 138 F and CPU Core at 99 F and casing is warm but not boiling hot. The graphics card is new from last week and based on other posts the temperatures at not high. After several hours of playing YouTube videos I seem to have stability at 2 bars intensity and immediate black screen if I go over 2 bars. Anyone got a concrete cause for this? My next step is to upgrade from Mavericks to Yosemite after which it is either back to Apple store or live with 2 bar screen brightness until it goes phut completely.

    Upgrading OS X WILL NOT solve  your issue, doing so will only make troubleshooting your problem much more difficult. If you had the computer serviced at an Apple Store, take it back immediately!

  • by Madhelp,

    Madhelp Madhelp Jul 24, 2015 11:24 AM in response to rkaufmann87
    Level 1 (0 points)
    Jul 24, 2015 11:24 AM in response to rkaufmann87

    I'm dealing with the same issue. My computer is a 27" 2012 iMac with the 6970M graphics card. Everything was great until a month ago when randomly my iMac would flicker and go black. I have an external monitor hooked up to the device and this monitor always stays on when I'm experiencing the issue. Eventually the iMac screen comes back, sometimes its a few minutes other times its like an hour. Usually it goes black out of sleep when it does happen.

     

    I took my computer to the store to have them look at it and they ran a bunch of test one of them being a VST test which it passed. The tech told me to have the faulty video card replaced it would have to fail the VST test . After she ran more test I got a chance to try and show her the issue. We booted the computer to my drive and put it to sleep, no issues. We put it to sleep a second time and sure enough the iMac did not come up, the external display come up fine. After a couple of minutes the iMac came back up which is what I've been experiencing.

     

    So will see how things turn out but I'm getting concerned about the iMac passing the VST test even though the tech saw the issue first hand.

  • by angbaby,

    angbaby angbaby Oct 7, 2015 10:32 PM in response to fiona.mac
    Level 1 (0 points)
    Oct 7, 2015 10:32 PM in response to fiona.mac

    I got same issue last week, 21'' model bought in 2012. It turns to same issue even into recovery mode.

    I'm using a mini dvi adapter connecting another display as termporary solution to keep mac running.

    I would follow to see how this issue walk out, but don't expect support says exchange your computer with new model, as it is not like a isolate problem at all.

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