[nycdunz]

sigh, i have a dual 2.7ghz powermac g5 and had this similar problem before awhile back. It would shut off randomly at times, i remember looking at the console logs and it said something about PMU forced shutdown.

But this time when i press the power button it won't turn on at all. It will eventually turn on if i keep pressing it or let it sit for awhile. But when it does turn on, it shuts off automatically. Everything was working ok until the people who came over to my house to work on the electricity today. They did something and cut the power temporarily and my g5 shut off. (I leave my computer running 24/7), after that I can't turn it back on no more. And when it does decide to power up, it randomly shuts down. and i have such a difficult time turning it back on and making it stay on. Anyone know what could be the problem? Sigh I really don't want to take my g5 back to Apple store, its such a pain. Anyone know what the problem might be? I'm not sure if I can blame it on the electrician or if my g5 is at fault. I mean it was working fine until the electrician came over to wire an extra outlet in my house.

My other computer in the other room also shut off when he temporarily disconnected the power, but I have no problem powering that one on at all.

Sigh...

what should I do? i remember taking it to the apple a long time ago and they did something, not sure what they did. I am desperately willing to try anything!

[seanc]

Try a PMU/SMU reset
How to reset the SMU on a Power Mac G5 (Late 2004) or Power Mac G5 (Late 2005)
Try moving the computer to a part of the house where there's a different circuit and then see if it'll power up. If it does, then it'll probably power up when you put it back.
Perhaps the power supply is dead.

[nycdunz]

I tried that already and it still randomly shuts off. Maybe I'm not resetting it properly? I pressed the button in and hold it in for about 10 seconds. I notice that when it boots up into the desktop, my clock/date is off, it says its like 1969 or something. Does this mean I need to replace the battery for the clock? I'm wondering if thats causing my computer to randomly shut down?

[sek929]

My G4 starting acting funky until I bought a new PRAM battery for it.

I also got the 1969 date before I replaced it.

[seanc]

Is your system liquid or air cooled? Does there seem to be any sign of leakage?
If you boot it from the Apple Hardware Test disc, does it still shutdown after a few minutes?
My only other obvious thought is the PSU. You run it 24/7, when was it last shut down for a period?

[nycdunz]

seanc, my system is liquid cooled... no signs of leakage as far as I know. I can't even boot into the system hardware cd cause it won't even turn on. Sigh. I have to keep pressing the button and unplugging and replugging it back in and eventually it will turn on, but it won't stay on for long, sigh.

The last thing that happened was when the electrician came over to my house to add an extra outlet in another room, he had to cut off the power, after that, my g5 had these issues, it was fine before that. I'm not sure why that would cause my g5 to act this way though. I mean we had power loss in the house plenty of times, and it would turn on fine after that. But this time I have no idea why it does that. Sigh. I can't even boot up using the system hardware disc to check my system without the thing shutting down.

do you guys think its my battery for the clock? Is that the same as the pram battery? I want to try to replace that before I actually take it into the apple store. Cause that thing is a pain to take in. And plus my warranty period is over. If I can fix it by getting new battery then I rather do it that way.

Can someone show me exactly what model of batteries(s) i need? And can i get them at Radio Shack or somewhere local? This is really stressing me out. I haven't touched my g5 for a few days now. However I did try to turn it back on the other day, and it still had problems powering up. and when it does power up, it will shut down after a few minutes, please help.

[Todd Madson]

My dual 2.5 ghz liquid cooled machine exhibited the same symptoms yours did, down
to the point where it would not boot.

The damage was that the liquid cooling system allegedly leaked into the system:
I never saw signs of a leak.

They needed to replace: power supply, motherboard, both processors, the fascia
for the liquid cooling system, and the liquid cooling system itself.

When I asked what they replaced they said "It's better that you ask what we
didn't replace, which was the superdrive and hard drive and case".

If I had not had Applecare it would have been one hell of an expensive repair,
moreso than the cost of the machine itself.

Check with your Apple dealer. These liquid cooled machines are kind of a
problem, I fully expect mine to leak again and probably after applecare is
done with.

[seanc]

It really does sound like either you have a coolant leakage that you can't see, like Todd above, or most likely that your power supply has failed.
How long have you had this machine running 24/7 for in this instance? It's quite common for something such as a failing capacitor to continue to run the system *ok* as long as it's powered on, but then when power is lost and you try to turn it on again, it's dead.

[nycdunz]

ever since i got the machine, i'm estimating maybe about 1-2 years now... sigh, i don't think its a coolant leak, because everything was working fine before the electrician came... how can a power outage cause a coolant leak?

[seanc]

Well it can't, really, but that's not to say it hadn't already been leaking. If there wasn't enough coolant in the system to keep the processors cool, the CPUs would get too hot and the machine would turn off, although I would have thought the fans would run very fast first.
I think the coolant leakage idea is a bit of a long shot now that I think about it, anyway.

Still sounds to me like the power supply has given up.

[nycdunz]

so what do you suggest i do? replace the battery for my PRAM/CLOCK or just take it to the apple store and pay to get it fixed?

[seanc]

Well you might as well replace the PRAM battery, since it's the cheapest option by far.
If that still doesn't work, you're probably going to have to take it down to the Apple store.

[nycdunz]

ok this is VERY VERY strange. I turned on my mac again yesterday, and so far it hasn't shutdown. So I decided to run the hardware test CD that it came with. EVERYTHING PASSED! Now my macs been on ever since w/o any problems.

What gives? The problem fixed itself. I have no idea what is causing it to shutdown like that before. The hardware tests show that everything passed w/o any problems. So what can it be?

[seanc]

Well if it was a power supply issue, the hardware test wouldn't pick it up, so I guess we'll never know.
I would suggest getting a UPS but if you turn it off, i'd be worried that it wouldn't come back on again.