Power Mac G4 won't turn on

[jenrafi]

Hi,
I went to turn on my Power Mac G4 this morning and only the fan would come on. No light. No computer start up sounds. No screen. Just the fan. I tried a new battery and that's not it. Any suggestions? Thanks!

 

[mad jew]

Try resetting the PRAM as a start.

What changes have you made to this machine recently, both in terms of hardware and software?

 

[jenrafi]

Absolutely none at all!

 

[mad jew]

Can you boot from the OSX disks? Are you able to get very far along the PRAM reset path?

 

[jenrafi]

yes I tried that. I hit the power button with command, option, P and R and that did not work. It seems to not even "boot up". Unplugged and waited then replugged in, and the only thing comes on is the fan.

 

[mad jew]

You tried booting from the CD, resetting the PRAM or both?

 

[jenrafi]

cannot open the cd. (running on OS 9

 

[mad jew]

Sorry, try booting from OS9 disks then.

 

[jenrafi]

whoops I meant I cannot open the actual cd drive. cannot even force it open!

 

[mad jew]

There's no little pinhole that you could shove a paperclip down?

Would it be possible to try entering Target Disk Mode? Also, have a look through this article.

 

[jenrafi]

ok got the cd drive open, stuck cd in and strated it. it doesn't read the disc I guess because it doesn't seem to be starting up. I push the button, and the light comes on while the button is pushed, then goes off (when it would normally stay on and strat up). The only noise I hear is the fan.

I could try the target disk mode to get the (of course important) files off this computer (thanks) I just have to run out to the store and buy a firwire cord.

Do you think the computer's dead? Is there anything else I can do?

 

[jenrafi]

I actually read through the article you suggested before but it didn't seem to apply to this situation because my fan DOES turn on. Thanks!

 

[thomasp]

Does the power light glow or light up while you press the power button? If so, this points to a PMU error, which is relatively simple to fix, but also relatively easy to kill your computer in the process.

 

[jenrafi]

yes it does only while I'm pressing it. Maybe I should leave the PMU error to a professional. (do you know what that stands for?)

 

[thomasp]

PMU = power management unit

The exact same thing happened with our G4 (but no fans) - the apple techsupport technician we phoned told us to find the "Reset PMU" button on the motherboard (quite a small one - may be near the battery), and press it once and once only.

 

[mad jew]

Yeah, I realise the fan turns on but I thought I'd post the link anyway. I agree with thomasp in that it's sounding like a PMU issue and so this is probably a more appropriate article. Like the first, it outlines a procedure (well, links to a procedure) for resetting the PMU, depending on the exact type of G4 you have.

Ideally, you'd back up your files with Target Disk Mode first.

 

[jenrafi]

ok thanks. My boss is taking it to a professional now. I always have trouble finding these articles on the apple site but everyone here always points me to the right direction. Thanks for ALL your help!!

 

[thomasp]

ok thanks. My boss is taking it to a professional now. I always have trouble finding these articles on the apple site but everyone here always points me to the right direction. Thanks for ALL your help!!

Hope it all goes well - by the sounds of things, it's a PMU problem which is hopefully easy to fix.

If you know your way around the insides of computers, or feel relatively confident in fixing/upgrading them, then the PMU reset isn't too taxing. But, if you're not too confident, it's best left to the pros, since you can totally fry your computer if you press the PMU Reset button too many times

 

[jenrafi]

umm yes perhaps if I was at home I would try it but since this is a business I feel it's best left to the pros. Thanks!

 

[disconap]

You can also manually reset the PRAM on a powermac G4; open it up (turned off, of course) and press the little grey button near the battery. Hold it down for about 2 seconds, then close up the tower and try booting. That would be my first call, other than checking all the wires and cable connections, stuff just comes loose over time...

Also, you may want to consider replacing the PRAM battery. If you have another G4 handy, swap out the batteries between the two and see if that works.

 

[tailwheel234]

Help!!!!

Ok, i thought this forum would be where I should look. I have a G4 that ran fine, then somethign happened. It is an older 466G4, but works great for what i need it for. then it stopped turning on suddenly. the pwr button light flashes sorta, and the fans run, and i hear the hard drive clicking as normal on power up, but doesn't go anywhere.... what do i try now? I am attaching a video of what it does when i fire it up. Thanks!!! Philip