Urgent problem. G5 red lights on. Won't complete startup. Please Help!!

Mar 10, 2010
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MacForum readers,
I'd be so appreciative for your help. This is the worst situation I have ever encountered on a Mac. :(

My G5 tower (purchased in around 2006) which has served me fairly well started to go on the fritz about a month ago. It would spontaneously go to sleep, --- often, and with not that many things running. A friend suggested I do this:
"Power down the G5 and unplug it for about 5 minutes. Then plug it back in and see if the problem reoccurs.

If it does, you may need to reset the SMU by pressing a small button inside the case. This web page has instructions on how to do this: How to reset the SMU on a Power Mac G5 (Late 2004) or Power Mac G5 (Late 2005)

Look for the "Late 2005" directions. Again allow some time to see if the problem persists."

That fixed the problem temporarily. For a couple of weeks, my computer seemed back to normal.

THEN tonight I was rendering a Final Cut Pro File and the following happened:

the screen went dark, the red lights on the G5 tower went on and the fan started to spin.
I shut it down.

I unplugged it. I reset the SMU button again.

I restarted the computer. It didn't get past the startup screen (which has never before happened, to my knowledge) and the red lights went on again.

What would you suggest I do? I'd very much be grateful for your advice. I've been waiting for the new MacPro to come out -- so I could replace this now totally unreliable computer. According to MacRumors, it has been 372 (Avg = 236) days since it was last updated, long overdue.
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Should I take it in to the Apple Store tomorrow? I'm worried the jostling of taking it to the store would damage it further?

THANK YOU so much all in advance.
Apr 7, 2009
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Whangarei NZ
Your Mac's Specs
27 iMac+Thunderbolt, iMac 21,
Welcome to the Forum. Power on and insert the Install Disk that came with the computer and hold the D key - select language and then Extended Hardware check. That may shed more light on where things are at. If that is all Ok do a reset of the PRAM here and let it boot after the third chime sequence.

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