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After I reset the pmu my G5 mac won`t start . I just get a light on top of the power on button. Before it was working fine. Note: I just pressed the PMU for 30 seconds and my Mac is back to normal. thank you

Power Mac G5 (Late 2005) To reset the SMU on a Power Mac G5 (Late 2005) computer, either use the steps listed above for the Power Mac G5 (Late 2004) or:

  1. Turn off the computer by selecting Shut Down from the Apple menu or by holding the power button until the computer turns off.
  2. Open and remove both the metallic outer door and the inner plastic air deflector.
  3. Remove the fan assembly immediately to the left of the processor module.
  4. Press the SMU reset button on the logic board.
  5. Replace the fan assembly, air deflector, and outer door.
  6. Turn on the computer. While open test, the 3.6 volt lithium battery.

Mayer is right, i might add that it’s important to press the reset button just once, best with a non condictive tool. Even a plastic toothpick will do.

Original Poster Answers own question I just pressed the PMU for 30 seconds and my Mac is back to normal. ''

I dont have an anwser but actually a question… My G5 shut off after I heard a popping noise. And will not power on… Does anyone know if this is the power supply? Or something? If you could please help that would be great… Thanks Justin