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  • darrenfromechuca Level 1 (0 points)

    Ikyo2004 it may have fixed your problem but I had a wired keyboard & mouse (no wireless at all) and I still had the problem. Give yours a week and see if it's fixed. In the end I sent my 24" back to where I got it and brought a new 27" imac with no problems at all.

  • Patachin77 Level 1 (0 points)

    the problem is the video card, run in support if the machine is under warranty

  • Jason Manning1 Level 1 (5 points)

    I just hope there is an admin out there to shut this thread down! To assert it is a video card issue or a USB issues or a software bug clearly shows abject disregard for the 30 odd  pages of posts since 2009. It is clear that wake from sleep is a problem affecting many people for many different reasons. If we were all to be more specific about the causes we would probably establish at least 5 different root cause problems. Mine I am conviced was software related, since resolved via osx upgrade, others clearly have hardware issues. Since we now though have a mix of os and hardware configs on the post I believe the thread to have to have become too ambiguous to be of use. I say shut it down!

  • gevezex Level 1 (5 points)

    Just had the problem again (3rd time in 2 months). I already had a efi update last week. So that does not solve the problem.


    Kernel Extensions in backtrace:

   [F4FEA23A-BEEF-313E-B4B8-0E2FB91BC0B9]@0xffffff7 f81591000->0xffffff7f81827fff

                dependency:[F63D4ABE-42DA-33EF-BADD-3415B0CB0179]@0xffff ff7f80863000

                dependency:[4B3F84DC-18B3-3897-BC56-4E3940878047]@0xff ffff7f80ca1000

                dependency:[FE536983-1897-3D6B-965E-24B5A67080DA]@0 xffffff7f80c69000


    Looks like a video card problem???

  • fan232 Level 1 (0 points)

    I was plagued with this problem until a combination of different tweeks and updates solved it. Most likely software related. My imac has been freeze-free for about a year now. This thread however has gotten completely out of hand. I totaly agree with 'Jason Manning1', this thread has become far too ambiguous to be of any practical use.

    Too many different root cause problems!

    I say shut it down too!

  • Patachin77 Level 1 (0 points)

    I apologize for my incorrect English. The problem, to summarize, is this: when the machine is in sleep mode for some time, then after several minutes to occur after hours, waking up the screen stays black. The machine turns on but no screen. To verify that this is the problem, just press the control volume and hear the typical sound. I called apple 2 times, I reinstalled mac os 3 times, I disconnected everything (Firewire hard drives, USB devices, external monitor) but the problem persists. Again, only when the machine is in sleep mode for so long. When I told the technician that the problem was with many Apple users, I have been advised to take my iMac in for service. Apple knows the problem. is a hardware problem, probably the video card. In fact the video card is one of the few components that are common to all the 454 posts before mine. In a few days my imac will go home and let you know what I have repaired. Luckily I had activated the Apple Care.

  • Almakos Level 1 (0 points)

    actually imac won't wake up not because it was sleeping for long time, but because it actually was not sleeping fully. What I mean is when it is supposed to enter sleep mode by standby timer, it puts display to sleep, but mac itself stays awake. you can tell by vents spinning and external harddrive lights are active. So trying to wake not sleeping mac sometimes doesn't wake up the screen in that case.

    To tell more, I was perfectly able to reproduce exactly same issue under bootcamp Win7 system. So those are some sad news.

  • volney Level 1 (0 points)

    Out of share frustration I have worked around the problem by doing the following. I have set Energy Saver in System Preference to "OFF" and set screen saver to start in five (5) minutes I have also set Desktop to change the screen every hour. Since doing this I have not experienced the problem and I put my system to sleep every night using the following method clicking the Apple symbol at the top right corner of screen then click Sleep and it wakes from sleep each day without any problem. I am not in agreement with the proponents of shuting down this post not until a resoulation is found for every person who is experencing this problem

  • Qholmes Level 1 (0 points)

    Yea i think there is still some good info here that might help people.. It is a big post because lots of people have this issue.. Apple should address it..


    I set my machine to not sleep and my display to turn off in an hour.. I still get this issue... Now one thing i have noticed is that if i have Parallels running with Win 7 Pro.. I dont get the problem....


    I already  had my iMac 27" into the shop for about 3 weeks of testing etc.. they ended up replacing the video card and i still had the problem as soon as i brought it home and plugged it in.



  • Darko Martić Level 1 (0 points)

    Doing some extra google research in the meanwhile, if I understood correctly the issue is connected with bluetooth usage (keyboard, mouse, trackpad), since both BT and WiFi use "similar" GHz range, and all those other microwaves (microwave oven, neighbours wifi...) are making that extra noise.

    Could this also be connected with this topic issue?
    I mean, I haven't tried with wired keyboard/mouse, but how do you know that Mac is running but the video card is just not displaying anything?



    Some people resolved this issue by installing Wifi router that works on 5 GHz...

    I resolved my Wifi dropout issue by switching to ethernet LAN



    Since I have BT keyboard and both Magic Mouse and Trackpad, my next step is to replace keyboard with wired/USB one (alu with numeric) and sell Trackpad, but I'm keeping Magic Mouse as there is no other mouse with gestures like this one, and it just sits nice in hand. Or is there? A wired/USB one?

  • Patachin77 Level 1 (0 points)

    sorry but we are not looking for work around the problem but the solution

  • Patachin77 Level 1 (0 points)

    not a problem with the bluetooth mouse and keyboard. Who does not solve the problem even with a wired keyboard and mouse

  • Qholmes Level 1 (0 points)

    Well like i said in my post.. my issue goes away totally if i am running Parallels and Win 7 Pro.. So my bet is on some kind of driver issue.


    I use the Bluetooth keyboard and a USB mouse and wired lan and an external HD for back up.. But somtimes my machine will boot up with no video on the main screen but my external monitor always works.. Oh i guess that is something else that i have plugged in... but it does the problem with just bare bones like it did at the rapair shop.. And supposedly they replaced the video card.


    I have my machine set to never sleep and it still does it.


    I want to sell this thing and i would like the problem to be gone first.. I have too big a concience to sell something that does not work perfect.



  • Plucker Level 1 (10 points)

    I called support about this a couple of weeks ago and they recommended a reset of the iMac by removing the power cable and leaving it for 5 minutes before restarting.


    This seems to have done the trick and I have now switched back from wired keyboard to bluetooth keyboard and a touchpad and haven't had a problem since.  YMMV.


    They did also say that there may be other steps in the resolution process including hardware issues so this may not work for everyone but thought I should post my experience.

  • Patachin77 Level 1 (0 points)

    News. I took my iMac in service for 2 problems: nothing happens on waking from sleep and screen dirt at the top left. They replaced the display and the black screen problem has never occurred at the center. I assume then that the problem for me was the display. I tested the machine for two days, in various configurations, and you are no longer experiencing the problem. If it should happen again I will inform you. Hello everyone and again, sorry for my incorrect english.

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