12-31-2008, 08:57 AM

We have a curious problem with a Power Mac G4 and I was wondering if any of you had ever heard of it. At first we thought the power supply was dead, but now I am not so sure.

The computer was working fine and we shut it down and unplugged it, moving it aside for a few days. When we plugged it back in, it would not turn on - no noise, no lights, just completely dead.

We tried holding down the on button, changing power cord, using a different outlet and all the other obvious things. Then we opened it up to see if any internal plugs had been knocked loose, but everything looked OK.

We assumed the power supply was dead and set it aside.

My coworker, who has a similar Mac had exactly the same problem. He unplugged his computer and it died. However he came in a week later, all smiles, saying that he had fixed it. Apparently, he opened it up, pressed a button on the motherboard and plugged it back in. When he pressed the on button, lights flashed, but it wouldn't turn all the way on. He read, in a Mac forum, that removing the date/time battery can fix it, so he tried that and now his computer works.

We tried this on our computer and it didn't help at all. The computer is still totally dead, but his story gave me hope that maybe it's not the power supply.

Have any of you heard of anything like this?

P.S. If I could get it to work for just an hour and get the documents off of it, I would be happy as a clam!

Thanks in advance for any help you can provide!

12-31-2008, 09:32 AM

Do you get absolutely nothing, or when you press the power button, does it briefly illuminate before fading off

12-31-2008, 10:07 AM

We get absolutely nothing, but my coworker got nothing until he pressed that button on the motherboard.

Of course we tried that and it didn't work, so...

12-31-2008, 10:25 AM

I have one other question too. We have another Power Mac G4 that looks the same. If this were a PC, I would simply swap out the hard drives, remove the data and switch the hard drives back, but I have heard this is hard to do on a Mac.

1. Are all G4s made with the same motherboard, cd drive, etc., so that if I swapped the hard drive it would recognize the other hardware in the computer?

2. How hard is it to do that on a Mac. Do you need special tools?

12-31-2008, 12:05 PM

Swapping HDs is easy 4 screws and pull off the two cables. A trick I have used in the past is to pull off the power leads to the HDs and use only the DVD/CD as the startup drive. The system has to start from the CD/DVD this way and once it has started plug in the power cable for the 250 and then go to Disk utility to format it.

I also seem to remember you have to install 9.2.2 to then install OS X so perhaps start by installing OS 9 and restart from within 9 and move up.

A thought - pull open the side of the mac and plug in the power cable with the door open. If I can remember, there is a red light on the motherboard that lights indicating power to the motherboard. If no light check for the fuse first inside the power supply I believe.

12-31-2008, 12:12 PM

Give it a go, you can either swap the start up drives, or just add the dead G4s drive to the second ATA bus (the one connected to the optical drive and acess its content from there.

Its just 2 plugs the power plug and the ATA plug/ribbon

01-06-2009, 12:24 AM

you may want to check, if it is not too late, that it is not the cmos battery. its the little green one, that is about half the size of a "AA" battery. I was given 5 of these G4's that were supposedly dead, replaced the batteries (cost me $25 with shipping) and they all booted right up.

Anybody want to buy a g4?

Rus