New 27" iMac i5 intermittently does not fully come up from sleep mode

Discussion in 'iMac' started by Charliebird, Mar 12, 2010.

  1. Charliebird macrumors 6502a

    Joined:
    Mar 10, 2010
    #1
    I have a new 27” iMac i5 and I’m experiencing an issue with it waking up from sleep mode. When I first received the machine a week ago I noticed several times that when I went to wake it up from sleep mode it wouldn’t fully come up. The system fan would start up however the screen would stay black. I did a reformat\reload of the OS (10.6.2) and the problem went away (so I thought). Last night the machine once again did not wake up properly. I tried putting the machine back to sleep without success. Finally, I powered it off using the power button and turned it back on. I looked at the log files and there wasn’t anything recorded in them about an unsuccessful wakeup from sleep or any messages at all during that time period. There was an error relating to an unexpected power failure (probably relating to it being turned off while sleep mode was engaged). The time stamp for this error was later around the same time the machine successfully booted up after I turned it off. I do not have any devices plugged into my machine or any software programs that should interfere with sleep mode.

    There is one thing that happened last night that might be related to this issue. I have a Brother Laser printer that dims the lights whenever I print. I used it last night while the iMac was asleep and I wonder if it’s related. It’s never been an issue with my PC’s or the 21.5 iMac’s I had before I upgraded to this 27” iMac.
     
  2. steadcd macrumors member

    Joined:
    Mar 26, 2008
    Location:
    Birmingham, UK
    #2
    This has happened to me about 3 times in 2 months with my 27 i5. Tends to be after a long sleep ie in the morning. I've had to power down as well. Tried lots of things SMC/PRAM reset, switching off all peripherals, altering the energy saver settings, but it did it again a few days ago. I think others have reported this but haven't seen a definite explanation. Bit annoying but infrequent. It seems the hard drive wakes but the screen stays black. Anyone have the answer? Maybe 10.6.3 will fix it?

    I've also had the computer randomly wake in the middle of the night, once with the screen coming on, a few other times the hard drive starts making noise but screen stays black. I've turned off automatic syncing with my apple tv in case this was somehow waking the i5 and hasn't happened since but that was only a week or so ago.

    The sleep behaviour in general seems a bit odd on this machine.
     
  3. Charliebird thread starter macrumors 6502a

    Joined:
    Mar 10, 2010
    #3
    I’m wondering if the 27" iMac i5 is overly sensitive to power fluctuations. An easy test would be to plug an uninterruptible power supply into the iMac and see if the issue clears up. Although, I’m not sure if I’m in the mood to spend an additional 100 dollars on this project.
     
  4. WilliamG macrumors G3

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #4
    Are you sure you've got no funky USB devices plugged in?
     
  5. WilliamG macrumors G3

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #5
    Also, anyone with a desktop PC should spend that $100 (more like $80 on Amazon) for a UPS. It boggles my mind that people spend the better part of $2k on a computer, but don't protect that "investment" with an $80 UPS. It doesn't only protect against power cuts and corrupted date when the power kicks off/on, but it also REGULATES the power that comes in. Get on, please.
     
  6. Sir Cecil macrumors 6502a

    Joined:
    Mar 31, 2008
    #6
    What brand/model do you use?
     
  7. WilliamG macrumors G3

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #7
  8. Charliebird thread starter macrumors 6502a

    Joined:
    Mar 10, 2010
    #8
    I'll right I just ordered one from Amazon. Thanks for recommendation! I purchased it from their warehouse section for $58 dollars. I'll report back if my sleep issues go away. It's strange but I'm surprised more people aren't commenting that they have the same issue. I'm wondering if I have another bad machine. :( I hope not since I'm very happy with the screen.



     
  9. WilliamG macrumors G3

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #9
    For $58, you can't go wrong. Everyone should have a UPS for a desktop machine, regardless of issues with sleep mode. :) Makr sure you plug the USB cable in that goes from the UPS to the iMac, so you get the extra options in System Preferences under Energy Saver.

    Good luck!
     
  10. aviva macrumors newbie

    Joined:
    Mar 13, 2010
    #10
    I received my new iMac 27" i5 5 days ago and have the same issues as the OP.
    Three phonecalls later with Applecare and the machine will be returned for an exchange next Monday.
    After having me go through a series of manipulations, like resetting the SMC, PRAM/NVRAM, wiping the hard disk and reinstalling the OS, it was determined by the Genius that it is hardware related.
    Before packing it up I did some more testing and it appears to me it is time related.
    If the machine goes to sleep and I wake it up after less than 45 minutes the screen comes on immediately. After a longer stretch of sleep, like an hour or two, the screen will come alive after about 4 minutes. After sleeping overnight it will not come on at all, only a reboot will do.
    I also tried the same in Bootcamp with Windows 7 and it (mis)behaves exactly the same.
    All this makes me agree with the Genius that it is an hardware issue.
    It's too bad I have to send it back as it has a perfect screen :(.
     
  11. Charliebird thread starter macrumors 6502a

    Joined:
    Mar 10, 2010
    #11
    That's terrible, good luck with your replacement iMac. My machine has only not woken up three times. Two of times were right after I booted it up for the first time. I wiped the system clean and reloaded 10.6.2. It's happen one more time since then. Fingers cross this doesn't because a bigger issue.



     
  12. WilliamG macrumors G3

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #12
    It sounds to me like some software running in the background is causing issues. I can't think it's a hardware issue, as that doesn't make sense to me at this time.

    Care to list what software you have running when it happens? Have you ever just done a fresh install, installed NOTHING else, put the system to sleep and then tried to wake it up some hours later?
     
  13. mystikjoe macrumors regular

    Joined:
    Jan 29, 2010
    #13
    yes i had a i5 for 2 weeks and a i7 now never had any trouble coming out of sleep mode move the mouse and i'm in
     
  14. aviva macrumors newbie

    Joined:
    Mar 13, 2010
    #14
    As I explained in my post, the Genius had me wipe the disk and only install the OS. So no software was running other than the OS when I did the tests (I did not modify any of the default settings). Later I installed a clean Windows 7 with Bootcamp and also there it has the exactly the same symptoms.
     

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