# Do I need a new power supply?



## DGNMRWRW (Jan 18, 2005)

I've got an old dual 533 graphite Powermac G4 that won't turn on. When the power button is pressed, it flashes on then right back off again. The fan inside the tower will spin, and that's it. Nothing else will ever happen.

Is this a bad power supply?

Anyone know of anything else that might cause this?

Thanks for the help.


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## bobw (Jan 18, 2005)

You might want to try changing the clock battery first.


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## podmate (Jan 18, 2005)

From my experience this points to a bad power supply, although there is a chance that the logic board is bad.  

If you want to price a power supply (or any other parts) go to http://partsolver.com/
You will need the part number: 661-2412-R

Although it doesn't look like partsolver has the powersupply in stock you might want to give them a call anyway.  I recently got a PS for my QS from them for $120.00 which is 80-100 less than anywhere else.

It looks like dvwarehouse (http://www.dvwarehouse.com/product_info.php/products_id/2050) has one available for 185.00.

good luck!


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## bobw (Jan 18, 2005)

Bad power supply and the fan wouldn't run.


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## DGNMRWRW (Jan 18, 2005)

I've already tried replacing the battery. Are you sure the fan wouldn't run with a bad power supply?


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## bobw (Jan 18, 2005)

The fan runs off the power supply.

 Try pressing the PMU button on the logic Board do not press a second time. 
 Disconnect the power cord first.
 The PMU button is next to the battery, near the corner of the board.

 Wait ten seconds and power it on and see if it works.


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## podmate (Jan 18, 2005)

The fan still running is the reason that I said it might be a bad logic board.
I've had 2 power supplies go bad (both in quicksilvers) and the fan still worked, but the computer would not boot.  I replaced the ps and the computers work fine and have been for 1.5 years and 2 months respectivelly.


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## DGNMRWRW (Jan 18, 2005)

Tried the PMU button, still the same results. When I look inside the tower after trying to turn it on, all I have is a running fan and a red light on the board.

Bad logic board? What is it going to take to fix that?


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## podmate (Jan 18, 2005)

about $500.00 (http://www.welovemacs.com/6612397.html) unless you can find  one on ebay.

Heck, for $525.00 I'll sell you my Dual 533. 

edit: included part number:
Power Mac G4 Digital Audio Logic Board (p/n 661-2397)


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## podmate (Jan 18, 2005)

You could try sending the mac in for service.
This company, DT&T Computer Services, Inc. Fremont CA) (http://www.dttservice.com/appledesktops/powermacg4agppci.html) claims to be able to repair the logic board for $250.00
I've never used them so I have no idea if they are any good or not.  

Anybody heard of them?


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## chevy (Jan 18, 2005)

Bad HD ?


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## andychrist (Jan 18, 2005)

Have you tried to boot from a CD, holding down the C key simultaneously with the Power button?


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## DGNMRWRW (Jan 18, 2005)

Yeah, no dice. Will a new logic board require professional installation? i.e. shipping it off?


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## Darkshadow (Jan 18, 2005)

If you don't have a place that fixes macs around, yes.

BTW, with a bad power supply, the power supply fan _can_ spin up for a second.  You'll hear it because while it's only on for a split second, it takes longer for it to stop spinning.  I had that happen to me.


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## DGNMRWRW (Jan 18, 2005)

My fan seems to be spinning continuously. Its the only part of the Mac that continues to run...


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## Darkshadow (Jan 19, 2005)

Hmm, well I definitely didn't have that one happening.


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## bobw (Jan 19, 2005)

The Logic Board can be easily replaced by yourself, unless you're all thumbs


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## bullseye (Nov 2, 2006)

DGNMRWRW said:


> My fan seems to be spinning continuously. Its the only part of the Mac that continues to run...



Hey DGNMRWRW----
Was just curious if you had ever resolved the problem with your power supply.
Did it end up being the ps or the motherboard?

Reason I'm curious is I'm almost the identical problem with my Quicksilver G4 right now.
If I hold the start button for a couple seconds, it'll start up to just after the chime but before the drive initializes and then shut back down on it's own and there's a high-pitch whine that seems to be coming from the power supply. The whine goes away if I unplug it.

Anyone?

Thanks!


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