orourke3
Level 1 (0 points)

Q: iMac G5 not powering on

I've got a 20" iMac G5 PowerPC (no iSight, no ambient light sensor). It won't power on. I plug it in and diagnostic LED 1 is on. I press the internal power button and LED 2 comes on for a second and there's a slight whurr noise and both LEDs go out and everything stops. After this, when I turn the power off at the wall, LED 1 comes back on before doing a fade out after a few seconds. I'm unsure how to head forward from here. Should I press the SMU button while the power is connected?

This computer came to me non-working (it did work, just a non-tech person didn't understand that it needed a HDD) and so I put in a new HDD and installed OSX. Everything worked fine. Then I left it and didn't boot it up for a few weeks (perhaps a month or two) and now I can't get the old thing to do anything!

Any suggestions would be greatly appreciated. Thanks.

PowerMac, Mac OS X (10.3.x), 20" iMac G5 (no iSight, no ALS)

Posted on Dec 23, 2015 2:44 AM

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orourke3

Q: iMac G5 not powering on

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  • by 20484paul,

    20484paul Dec 23, 2015 8:18 AM in response to orourke3
    Level 2 (260 points)
    Dec 23, 2015 8:18 AM in response to orourke3

    Try reseting the smc.

  • by K Shaffer,

    K Shaffer K Shaffer Dec 24, 2015 12:13 PM in response to orourke3
    Level 6 (14,582 points)
    Desktops
    Dec 24, 2015 12:13 PM in response to orourke3

    Another item these Macs need, especially if not plugged in or replaced, is the PRAM

    or clock battery that resides on the logic board. This may afflict the start up sequence.

     

    Usually those batteries last a few years, and then get replaced. They do not recharge.

     

    There also are potential issues with the power supplies and a few locations on the

    board where electronic components can exhibit failure. Documented, and some do

    show visible failures when they swell or appear distorted.

     

    Inspect the Capacitors? See the iFixit.com repair guides for G5 iMac models.

     

    Good luck!