1 2 Previous Next 24 Replies Latest reply: Jan 17, 2014 12:43 PM by mrbofus Go to original post
  • 15. Re: iMac display turning off randomly with external monitors
    alisafromrus Level 1 Level 1 (0 points)

    hi all

    will my iMac consumes less energy if i use a black descktop background

    ))

    thanks

  • 16. Re: iMac display turning off randomly with external monitors
    mrbofus Level 1 Level 1 (5 points)

    alisafromrus wrote:

     

    hi all

    will my iMac consumes less energy if i use a black descktop background

    ))

    thanks

     

    My understanding is that if you are using a CRT monitor, a black background uses less energy; but on a LCD monitor, a white background uses less energy.

  • 17. Re: iMac display turning off randomly with external monitors
    enah Level 1 Level 1 (0 points)

    similar issue. For me the screen is nearly permanently off but I can log into the machine using logmein - it is running fine. I am getting the following:

     

    30/08/2013 11:30:05.000 kernel[0]: RTC: Maintenance 2013/8/30 10:30:05, sleep 2013/8/30 08:44:29

    30/08/2013 11:30:05.000 kernel[0]: Previous Sleep Cause: 5

    30/08/2013 13:15:44.000 kernel[0]: RTC: Maintenance 2013/8/30 12:15:44, sleep 2013/8/30 10:30:36

    30/08/2013 13:15:44.000 kernel[0]: Previous Sleep Cause: 5

    30/08/2013 14:10:34.702 WindowServer[93]: handle_will_sleep_auth_and_shield_windows: no action for lock state 1

    30/08/2013 14:10:34.704 WindowServer[93]: handle_will_sleep_auth_and_shield_windows: no action for lock state 1

    30/08/2013 14:10:34.000 kernel[0]: Previous Sleep Cause: 5

    30/08/2013 14:36:39.377 WindowServer[93]: handle_will_sleep_auth_and_shield_windows: no lock state data

    30/08/2013 14:36:39.380 WindowServer[93]: handle_will_sleep_auth_and_shield_windows: no lock state data

  • 18. Re: iMac display turning off randomly with external monitors
    mrbofus Level 1 Level 1 (5 points)

    enah wrote:

     

    similar issue. For me the screen is nearly permanently off but I can log into the machine using logmein - it is running fine. I am getting the following:

     

    30/08/2013 11:30:05.000 kernel[0]: RTC: Maintenance 2013/8/30 10:30:05, sleep 2013/8/30 08:44:29

    30/08/2013 11:30:05.000 kernel[0]: Previous Sleep Cause: 5

    30/08/2013 13:15:44.000 kernel[0]: RTC: Maintenance 2013/8/30 12:15:44, sleep 2013/8/30 10:30:36

    30/08/2013 13:15:44.000 kernel[0]: Previous Sleep Cause: 5

    30/08/2013 14:10:34.702 WindowServer[93]: handle_will_sleep_auth_and_shield_windows: no action for lock state 1

    30/08/2013 14:10:34.704 WindowServer[93]: handle_will_sleep_auth_and_shield_windows: no action for lock state 1

    30/08/2013 14:10:34.000 kernel[0]: Previous Sleep Cause: 5

    30/08/2013 14:36:39.377 WindowServer[93]: handle_will_sleep_auth_and_shield_windows: no lock state data

    30/08/2013 14:36:39.380 WindowServer[93]: handle_will_sleep_auth_and_shield_windows: no lock state data

    Did the problem start for you after installing the 2013-003 update?  If not, when did the problem start?  What version of OS X are you running?  What model iMac?

     

    Have you tried not letting the iMac sleep?  What happens then?

  • 19. Re: iMac display turning off randomly with external monitors
    enah Level 1 Level 1 (0 points)

    no change when sleep is disabled.

     

    Going to plug in a monitor and try a fresh install.

  • 20. Re: iMac display turning off randomly with external monitors
    mrbofus Level 1 Level 1 (5 points)

    enah wrote:

     

    no change when sleep is disabled.

     

    Going to plug in a monitor and try a fresh install.

     

    Did the problem start for you after installing the 2013-003 update? If not, when did the problem start? What version of OS X are you running? What model iMac?

  • 21. Re: iMac display turning off randomly with external monitors
    enah Level 1 Level 1 (0 points)

    It started on the 23rd of August after some updates - I am not sure if it's the update you mention. Ater that I upgraded to Mountain Lion - it's running the latest version available.

     

    Strangely the screen came on for two hours yesterday and then went again - despite showing no light on startup.

     

    It's an early 2008 iMac. I guess it's possible the screen is just gone, but if that were the case you would think there would be no response at all from the screen.

  • 22. Re: iMac display turning off randomly with external monitors
    mrbofus Level 1 Level 1 (5 points)

    enah wrote:

     

    It started on the 23rd of August after some updates - I am not sure if it's the update you mention. Ater that I upgraded to Mountain Lion - it's running the latest version available.

     

    Strangely the screen came on for two hours yesterday and then went again - despite showing no light on startup.

     

    It's an early 2008 iMac. I guess it's possible the screen is just gone, but if that were the case you would think there would be no response at all from the screen.

    Yeah, that is weird.  It's also fairly unusual for a screen to just die.  I was hoping that we could nail the issue down to the 2013-003 update, but it looks like that might not be the case.

  • 23. Re: iMac display turning off randomly with external monitors
    mrbofus Level 1 Level 1 (5 points)

    There is another similar thread here ( https://discussions.apple.com/thread/4062983 ) and in response to the some of the common possible causes listed there, here is my experience.

     

    Temperature: For me, this was not an issue.  My iMac is in a room that is anywhere between 70-80 degrees Fahrenheit and I've had the iMac display randomly turn off independent of the room temperature.  That is, keeping the room cooler didn't keep the iMac display on.

     

    Video card:  This too seems to not be the issue for me.  I have two external monitors connected to my iMac and when the iMac display goes blank, the two external monitors work just fine.  There's no hiccup or anything, just the iMac display going dark.  Additionally, I took my iMac in to the Apple Store (by the way, the 27" iMac is a pain in the butt to lug around!) for the 1TB hard drive replacement program and also for the AMD GPU replacement program.  The hard drive was replaced, but the Apple techs said that the GPU was not eligible for replacement because it didn't fail when they ran the diagnostic.  They said they would only replace the GPU if it failed under a specific test. 

     

    Backlight:  This did not seem to be the issue for me.  When my display went black, even if I shined a flashlight into the iMac display, there was nothing.  I couldn't see a faint trace of anything, it was just black.

     

    Software:  So far, in my case, this seems to be the most likely culprit.  I did a clean install of Mavericks after getting my iMac back, and it's only been half a day, but so far, my iMac has been able to go to sleep and wake up with no display issues.  Previously, upon turning on my iMac, the iMac display was guaranteed to intermittently or permanently (for that boot cycle) go black within an hour.

     

    Previous to doing a clean install, I tried all the normal things to fix the issue, including repairing disk permissions, resetting the SMC, unplugging external displays, etc...but none of those worked.  So for those of you still experiencing this issue, as much as a pain it may be, a clean install might be worth a shot.

     

    If the problem returns for me, I will report back.

  • 24. Re: iMac display turning off randomly with external monitors
    mrbofus Level 1 Level 1 (5 points)

    Aaaaaand, the problem has returned for me.  #*%&#@*(@(!*@*$#)@((@&$^

  • 25. Re: iMac display turning off randomly with external monitors
    mrbofus Level 1 Level 1 (5 points)

    If anything, the problem is now worse for me.  My current and previous energy settings are that the computer never sleeps and that the displays turn off after 30 minutes. Previously, at least if I stopped my system from sleeping, the iMac display would work until the next restart, meaning I could get at least a few weeks of use on all the displays.  Currently, the iMac display never turns on when I start working on the computer, even though the system wasn't sleeping (the displays turn off but the computer doesn't go to sleep, which is the same setting as before I did the clean install).  The iMac display will turn on at some random point (usually after I've been using the computer for an hour or more) and then stay on, but once the display turns off (overnight, for example), it won't turn on again for at least an hour after I start using the computer again.

1 2 Previous Next