[ryanmk2004]

When my Power Mac goes to shut down, instead of turning itself off it just reboots. Also when it starts up it doesnt seem to make the startup noise like normal through the internal speaker, i dont have other speakers hooked up at the moment. I havent changed anything lately. Any idea what it could be. Other then rebooting instead of shutting down it works fine.

powermac g5 dp 1.8

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nevermind. it seems it didnt like the monitor i was using temporarily. i switched back to my normal monitor and all is well. thanks anyway.

[Big Mac]

Most would counsel that the PMU should be reset. That's what it sounds like to me. Wow, I just found out Apple changed the PMU situation again. The G5s that Apple designates as (Late 2004) don't have a PMU but rather an SMU, and the way to reset its SMU is to simply shut down and then unplug the computer for fifteen seconds:

http://docs.info.apple.com/article.html?artnum=300341

On the other hand, if you have an earlier G5 you'll need to press the PMU reset button on the motherboard. I cannot seem to find the specific Apple document for that procedure, but you'll get what you need through Google. I really wish Apple would differentiate between models in a more precise way, because this document seems to indicate there is a Rev C G5 being sold now. Does anyone know more about this?

[Krypton]

My Dad had this problem with his G4, turned out that is was caused by USB devices - having a high powered device in a low power port (e.g. in the monitor hub).

Swapping the devices around fixed the problem.