Imac wakes automatically from sleep mode

in Genius Bar edited January 2014
For some days now my Imac wakes up out of sleep mode sometime during the night (between 12:00 and 3:00 am.). I suspected that it could be some app updating, but I have very few third party apps and I have checked all of the apps installed and none are set to auto update. I think this problem started after the last iTunes update but cannot be sure. However this is very disturbing when the mac comes on at night and lights up the whole room. I am now forced to shut down every night instead of going into sleep mode.

I also checked the disk permissions and had those repaired.

I have no idea what else it could be. Any suggestions on how to solve this problem?


  • Reply 1 of 7
    How is it connected to the network? ... ethernet or WiFi ?
  • Reply 2 of 7
    Originally Posted by KingOfSomewhereHot View Post

    How is it connected to the network? ... ethernet or WiFi ?

    It is connected via WiFi
  • Reply 3 of 7
    Ok... That rules out my first thought.

    Obviously you have SOME thing running in the background that triggers the machine to wake up and do SOMEthing....

    What is listed in your"startup" items in sys prefs?

    Next would be to look through Activity monitor and see what processes are still going when you have all apps terminated. Hopefully something will stick out.
  • Reply 4 of 7
    Activity monitor shows no processes running when apps are terminated, but I agree, something must trigger the machine to wake up.

    In the "startup items" there are a few apps listed but none are activated. That is if I looked in the right place. (system preferences-accounts-log in items)?
  • Reply 5 of 7
    This sucks... But MY next step would have to be sitting up with it to see what processes are active when it wakes itself up.

    SOME app seems to have installed a "helper" that phones home or something.
  • Reply 6 of 7
    sequitursequitur Posts: 1,901member
    I had the same problem with a G4 tower and 22" ACD . After taking them both in to the Apple store several times, they finally decided the problem was in the monitor. Fortunately, it was still under warranty and the store shipped the ACD back to the factory. If memory serves, it may have been a bad capacitor in the monitor. I had to wait about two weeks to get it back, but it stayed asleep from then on.
  • Reply 7 of 7
    Update: Last night before going to bed I set OSX so it does not check for updates automatically on the presumption that this could be the problem, meaning that perhaps OSX checks for updates during the night hours when the servers are not so busy. Well to make a long story short, it did not wake up from sleep as the nights before. Off course I am not sure if this is/was the problem and if so this is just a work around and not a solution but at least it lets me sleep. I guess in future I will just have to do the updates manually. I will put in back on auto update tonight and see what happens.

    Will update again tomorrow.

    Update 2. OSX did not wake from sleep last night even though the auto update was on. The problem seems to have solved itself at least for the time being. What caused it in the first place remains unknown. One of the mysteries of our time. Perhaps we will never ever find out why!!
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