Question about Apple Power Mac G5 Desktop

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Power PC G5 Dual 2.5 sudden shutdown and no reboot

Recently I replaced the power supply (blown) from my G5, after that is shows an unpredictable behavior. It is running great for a week, all of a sudden it shutdown the video, ramp up the fans, front white led on. When you reboot, front led light up but turns off quickly, fans start, gongs but suddenly you can see front led turn back on and simultaneously a red led deep inside the machine (not the leds close to RAM) and video never begins and stays there until fans ramp up after a couple of minutes. All leds close to RAM off.

Ran Apple Diag disk and passed all, but when you try a thermal calibration it says either radiator pump error, or to remove/replace clear plastic door.

What could it be?

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  • localhost Feb 14, 2009

    It is not the airflow cover unseat light, which is by the RAM. and the 2.5 GHz does not have the 7 diagnostic LED's, that's only the last generation of G5's. I have the same problem as OP, any clue what these red LEDs deep in th machine might indicate?

  • Sean Cole
    Sean Cole May 11, 2010

    Did u manage to fix this problem?

  • Sean Cole
    Sean Cole May 11, 2010

    Hi Marcos845,

    Sorry to hear you're having problems with your G5. If you open the side panel (but not the deflector shield) there are 7 LEDs next to the RAM ports - 6 directly to the left and 1 just slightly below and to the right of the others. Let me know which ones are lit numbering them from top to bottom.

    All the best


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In G5 always the cover should be closed properly if not it will start the fan very fast like a blower and the red leds will be on showing that the heat is over so please check that the cover is closed and locked from behind so itworks smooth and the power supply is standard or normal
u should always use genune parts with mac..

Posted on Jan 04, 2009

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