# Power Mac G5 start up problem



## brettg (Feb 19, 2010)

I hope you guys can help me out.  I've been using my wife's PC and it's killing me.  On my G5 when power button is pressed chime sounds and monitor power light comes on but screen stays black until fans go into overdrive.  When the fans start roaring I just power down the machine.  The power light on the display stays on until I unplug it's power source.  I've tried resetting the PRAM but no second chime ever comes and I reset the SMU.  I also tried holding just the option key down at start up but nothing there either.  I got this G5 in early 2006 and have had little problems with it.  About late December this started and after a few boot ups I got a Kernal Panic.  I didn't know what it was so I don't have the info from it.  Sorry.  After that nothing on the screen no matter what I try.  No LED lights on except 4 in yellow and 3 in red at start up.  Any suggestions?  Thanks for any help.  
P.S. I am an idiot when it comes to knowing how this stuff works so sorry in advance.  This has prompted me to actually learn about the machine I am using.  It's even more pathetic that I didn't do this before since I need my G5 for my side business.  I guess it's true that we don't know what we have until it's gone


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## djackmac (Feb 19, 2010)

If you are not adept at troubleshooting Apple equipment you are going to have to take it to an Apple authorized shop to get it looked at. The Apple store more than likely won't touch it and a non Apple shop, unless they have a very experience Mac tech on staff probably doesn't have an outstanding shot of giving you an accurate diagnosis and they won't be able to get parts. Having repaired many of these machines, experience is telling me it is more than likely a bad processor. But the best thing to try at the time is to reseat the processors because the natural vibrations of the machine can cause a processor to not be fully seated to its base on the logic board (slim chance but it happens). Beyond that the next best bet is to swap the processors around (i.e. bottom processor in top spot, top processor in bottom spot). If it starts acting better with this configuration you can pretty much bet one of the processors has gone south. Unfortunately the swapped processor configuration running on a bad processor will still be problematic and the fans will blow full tilt because the machine will need to be recalibrated.


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## brettg (Feb 20, 2010)

How much skill is involved in switching the processors locations (anything other then unplugging and plugging back in)?  Any tips on the process?  Should I try moving anything else around if this doesn't work?  Do you know of any *good* books that could help me learn how to work a little on these machines?


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## MisterMe (Feb 20, 2010)

brettg said:


> How much skill is involved in switching the processors locations (anything other then unplugging and plugging back in)?  ...


A lot. Power Mac G5s are not to be trifled with. These computers have processor/cooling unit modules. Each processor is matched to its cooling unit. They are not available as loose units. It is my understanding that when you replace one of these modules, that you must calibrate it so that the cooling system works properly. 

If the things that I am telling you look like Greek to you, then take you computer to a technician who understands "Greek."


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## Jesse714 (Feb 21, 2010)

http://support.apple.com/kb/HT2652?viewlocale=en_US


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