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  1. #1


    Member Since
    Jan 13, 2010
    Posts
    4
    Power light is on, but no response from G5 tower
    Hi,

    Our G5 Power Mac was in sleep mode over night a few days ago. The power went out during the night sometime and came back on about 2 hours later. Both our Mac Book Pro and G5 were in sleep mode, the MBP is fine, no damage at all. However, the power light on the front of the G5 is on, but the computer is not on, the external hard drives are off and the monitor wont come on. I tried to hold the power button down to shut off the light, but nothing happens no matter how long I hold it. The only way to make the light go out is to unplug it from the wall.

    After I plug it back in, the light instantly comes on again by itself and the Mac just sits there doing nothing. The G5 is on a surge protector if that helps the diagnosis.

    Thanks in advance for any help.

  2. #2

    chscag's Avatar
    Member Since
    Jan 23, 2008
    Location
    Fort Worth, Texas
    Posts
    47,975
    Specs:
    Late 2013 27" iMac, iPad 3, iPhone 6s+, iPhone 6+, 3 iPods, El Capitan
    The G5 may have suffered damage to its power supply from the power off, power on, during the night. Power surge strips (no matter how sophisticated) do not provide adequate enough protection from power hits and line surges. In some instances they may mitigate it somewhat, however, the best protection is an isolated UPS system.

    Your machines were in sleep mode which means they were still on but in low power state and vulnerable to line hits.

    See if this trouble shooting article helps: LINK

    Regards.

  3. #3


    Member Since
    Jan 13, 2010
    Posts
    4
    Thanks for the link, however I didnt see anything there that sounded like my problem. They had some info on power supply problems but the users were experiencing fan noises, mine is dead quiet with the front light on and thats it, nothing else works.

    Might be time to make an appointment at the Genius Bar. I just hate to spend anymore money on this old G5 tower.

  4. #4

    hughvane's Avatar
    Member Since
    May 18, 2008
    Location
    Banks Peninsula, Canterbury
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    3,306
    Specs:
    MacMini 2.4, 8 Gb, OS 10.11 and 10.6; MacBook 2.4, 4 Gb, OS 10.6.8
    Unplug the G5 from the wall again, but this time leave it off for several hours.

    Secondly, open up the G5 while it's off, and replace the PRAM battery (not a big cost). If I were you I'd also pull the RAM modules, and then reseat them firmly. Again, wait for an hour or two before trying a restart.
    ABCDEFGHIJKLMNOPQRSTUVWXYZ
    Please post your Mac (or other) specs and MacOS version in your post, your profile or your signature. It helps us to help you better.

    I'm leaving now to go and find myself. If I should return before I get back, please ask me to wait.

  5. #5


    Member Since
    Jan 13, 2010
    Posts
    4
    Thank you, I'm trying it right now.

  6. #6


    Member Since
    Jan 13, 2010
    Posts
    4
    A quick update. Its working perfectly again. A friend suggested taking the cover off and pushing the PMU reset button on the logic board. Did that and it fired right up when I plugged it back in.

    Thanks again

  7. #7

    pigoo3's Avatar
    Member Since
    May 20, 2008
    Location
    U.S.
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    34,191
    Specs:
    2011 13" MBP 2.3ghz, 8gig ram, OS 10.8.5
    Quote Originally Posted by Jumbo Jet View Post
    A quick update. Its working perfectly again. A friend suggested taking the cover off and pushing the PMU reset button on the logic board. Did that and it fired right up when I plugged it back in.

    Thanks again
    Congrats! Hopefully everything will remain stable.

    - Nick
    - Too many "beachballs", read this: Beachballs
    - Computer seems slower than it used to? Read this for some slow computer tips: Speedup
    - Almost full hard drive? Some solutions. Out of Space
    - Apple Battery Info. Battery

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