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Why does my 7 year old iMac G-5 shut down automatically when asleep?

478 Views 3 Replies Latest reply: Sep 6, 2012 2:01 PM by Kenichi Watanabe RSS
Brainbytes Level 1 Level 1 (15 points)
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Sep 5, 2012 8:23 AM

Why does my 7 year old iMac G-5 shut down automatically when asleep? Does it need a new battery? When sleep energy setting is off, this does not occur. Please advise! Thank you!!

  • Kenichi Watanabe Level 7 Level 7 (30,005 points)

    It may be the PRAM battery.


    You can also try resetting PRAM



    and then using this procedure to reset SMU (power management)



    to see if that makes any difference.

  • Kenichi Watanabe Level 7 Level 7 (30,005 points)

    One other thing you should check is to make sure the iMac has a good power connection.  If you are currently connecting it to an old or over-crowded "power strip,"  as a test, try connecting it to a direct wall connection by itself.


    What you said with (1) sounds like it could be a power supply issue.  By unplugging it, you are doing something like the SMU reset, and that "resets" the power supply so it works again, until the next time it has a problem.


    I don't know what is causing (2).  Is this sound coming from the speakers, or something mechanical inside the iMac?


    And, it may be a dead or weak PRAM battery.  If you disconnect it from power, plug it back in, and start it up without an Internet connection, is the time and date set to some odd date/time?


    If the main problem is related to sleeping, you may want to just set Energy Saver to do Display sleep, but NOT Computer sleep.  That's actually how I use my iMac all the time.  When you know you are not going to be using the iMac for a few days, shut it down (power off).  If it works reliably that way (when you are using it), keep using it that way until you get a new Mac (or it fails in a more serious way).  In the mean time, you should have a good data backup plan in place (like using Time Machine if your OS is Leopard).


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