My IMac keeps turning off

It is turning off and I doubt it is overheating because it is only making it a couple minutes at best.

If there is a problem with the fan it could overheat in seconds...  Even a dusty heatsink can cause the CPU to overheat gradually as the heat dissipation is affected.

Can you turn it on immediately?  Does how soon you turn it back on again affect how long it is between shut downs?

Since I just received the machine I have only turned it on a couple times.  But I do recall turning it on this morning and running it for about 2-3 minutes.  Once it turned off I tried rebooting and it immediatley shutdown at startup.  

That would fit the symptoms of overheating.

Are you able to open it up and check the fan is working, free of dust and debris?

I have never opened an IMac.  Is this a any different from working on a pc?  If so, is there good instructions out there?

No - a Mac is the same in all respects.

Okay, so I took the machine apart and it looked very clean.  I did spray with can air in the fan area.  I turned the machine on with it open and notice that the fans are both working.  I closed the case and turned the machine back on and it ran for about 3 minutes before shutting down.  I did listen more closely and heard a clicking sound periodically that sounded like it could be coming from the hard drive.  Any thoughts?

I do know my friend used it last night before giving it to me to back up all his music.  I know it was on for a long period of time then.

Open DIsk Utility and find out what the SMART Status of your hard drive is.

The SMART status says verified.

Sometimes the simplest thing can go wrong with the high tech machine.  Your power cord could be defective.  Do you have another one you can use instead?

Well the power cord is not the problem.  I still can hear something that clicks inside the machine.  turned the machine on and let it sit at the desktop for a couple minutes and then it shut off.

The clicking is probably from hard disk, and it may be failing all right, but it is probably not causing the computer to power off.  So my guess is that you probably have two issues going on.  I was trying to help with the power issue only.

So I have tried a new power supply, checked the fan, blew out the inside but still nothing has worked.  Does anyone have any other ideas?

Any ideas?

Sorry, I'm stumped.  Is there an Apple Genius Bar near you?  If yes, take your machine over there and let them tear their hair out trying to diagnose it.  (There is no charge for their services.) Good luck!

If the Mac has an OS setup or other kind of bootable disc/media, try booting from that instead of the Hard Drive.

(Hold down alt/'option' on the keyboard during boot, then select the disc image)

If your machine can boot onto other media without shutting down it will be your Hard Drive.

Try that and post your results if it lasts longer than about 5-10 mins.

Did you run Apple's Hardware Test:  http://support.apple.com/kb/HT1509

See also:  http://www.thexlab.com/faqs/aht.html

Okay I brought in to the apple store and it looks like the logic board has some bad transisters.  Any thoughts?

Does anyone know if I can plug the mac hard drive in to my pc and extract some files?

Yes, but you will need third party software to allow your PC to recognize your Mac drive:

http://www.mediafour.com/products/macdrive/

We never did do an exact model request. This may not hurt for the author to post the exact model/specs as some emacs and I macs had either official and unofficial capacitor warranty extensions.

I went to the Istore and Genius bar.  They said I would have to pay for Parts and no labor.  But the logic board was like $350 bucks.  I assume by this statement from the store that it is not under warranty.  However the following is the machine information:
Model #A1058
100-120V-, 50-60Hz, 5.0A

Actually I bet the store is really pocketing the labor because Apple is really buying the board: read below. We really need to know serial number and revision


.I'm sure you guys already know about this but I thought I'd go ahead and post if by chance someone still needs the info. I actually just found out while researching an iMac that I'm working on.

Apple will repair or replace any problematic iMac G5 1.6ghz logic boards free of charge thru a sort of recall for up to three years after the purchase date. The caps in these 'test drive' iMacs were bad and bulged when they heated up...Here's the Apple website link:

http://docs.info.apple.com/article.html?artnum=302181

Or just search for iMac G5 Repair Extension Program for Video and Power Issues...

The serial # is W84480NAPNX

It does appear to be a 1.6 machine, but I am on the phone with Apple and they say I am out of warranty because I did not buy the apple care plan.

Keep trying every other day be nice but firm. Tons of people have got theiir boards fixed free. Once there is an extension Apple will usually honor it even after the extension has expired. Just be persistant and keep trying to work your way up the ladder. Research this and bombard them with proof of all the people whose machines were fixed. Keep at it until they fix it.

They actually agreed to fix it yesterday!!!!!!

Thanks for all you helped troubleshoot this problem.  Not really sure how to assign points because so many helped.