[sek929]

After a short power outtage I went to turn my Mac back on (G4 733 QS) and the power button lights up when pressed, but nothing else happens.

Craptastic!

Where the hell do I start?

[baw]

Press the PMU reset on the mlb?

[sek929]

After looking at Apple.com they don't seem to have any diagram of where it is, any ideas?

[Laurence]

First thing, unplug it and open the case. There should be a reset switch on the motherboard. Hold the reset down while you plug in the computer and keep it held down when you turn on the computer. If this doesn't help then reseat the RAM, video card, etc... ie make sure all the connections are good and then power it up again. If this doesn't help, see if you can boot off the CD. If you can boot off the CD, try repairing the boot drive. If this doesn't help, try something like Disk Warrior on the drive. If you can't boot off the CD, disconnect the internal hard drive and see if you can boot off the CD then. If it boots with the internal drive disconnected then the drive is probably damaged. If it still doesn't boot it could really be dead... (By that I mean that replacing the motherboard is more expensive than a new Mac Mini so its not worth it) The good thing about it being the motherboard is that your data is probably still intact and with an external FW/USB case you could probably copy the data onto a new computer.

[Laurence]

The PMU reset is the only button on the motherboard. Just look carefully. Its about 3mm in diameter and If I recall its a light grey color. I also recall that it is visible without removing drives/RAM/Heatsinks, etc.

[sek929]

Found it! Worked! I'm not shedding my hair anymore (though I may have a new grey strand)

Thanks for your quick replies, I was across the street at a neighbor's house using their internet, so I appreciate the speedy responses.

My power has gone out countless times and this has never happened before, could this be a symptom of a larger problem?

[seanc]

It's most likely a symptom of your PRAM battery being dead. Replace it and everything should be hunky dorey.

[Googer-Giger]

I had the same thing happen to me with my G5, where there was a pop and the power button would light up, I brought it to apple, they had to replace my power supply.

[Captain Curt]

I'm having the same problem on my Mac. My previously rock solid Mac slowly crashed. I replaced the hard disk drive and then reinstalled Tiger. Initially, I thought it was a problem related to the Radeon 9600 Pro PC/Mac video card. Sek929 do you use a Radeon card in your Mac? I have replaced two batteries, a hard disk drive and my ram passed a ram diagnostic test I downloaded. I still have the same syptoms-the power button lights up when pressed but then only a dark screen. If I press the PMU button with no power applied then push the power button everything works perfectly (except of course having to reset time and date). Lately, I've dismissed the idea of having a corrupted operating system. All of this is making me save faster and harder for a Mac Pro. Any insights anyone?

[Captain Curt]

Googer-Giger I didn't see your reply before I posted mine. Maybe a new power supply is the answer. Thanks.

[sek929]

I have a GeeForce 2MX

[Captain Curt]

Thanks sek929. The more info the better for my diagnosing my Mac.

[IceEnclosure]

G4 533 DA with GeForce2MX.

I've had power outages that simply required a press of the power button to get started back up.

I've also had power outages that caused the same thing you experienced. (needing to press the PMU reset)

I think it's just a result of how the power gets zapped. I don't think it's a sign of bad things with your computer. I think.


Laurence: holding down the PMU while plugging in and turning on the computer?? Is that just on the Quicksilver models? I though a quick press was all that was necessary.