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The PowerMac G5 is a desktop computer first produced in 2003 by the Apple Corporation. This guide will review the repair process of an Apple PowerMac G5 model number A1047 EMC 2061 from 2004. It was discontinued in 2006 as part of the Intel switch first to developers then consumers.

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G5 won't boot with video card.

Hi all,

So the other day I came home to find my powermac g5 frozen with the fans going crazy. After a hard reset the machine would no longer boot any further than the grey apple (kernel) stage. After pulling the video card the machine would boot up and I could log in using remote desktop from my laptop.

The machine ran that way for a couple of days until I got a new video card. When I put the new video card in the machine would not boot again.(The new card is exactly the same one as the old one)(ATI Radeon X800 XT mac edition).

After pulling the card the machine still wouldn't boot (exact same behavior as with the card) until I let it sit unplugged for 20 minutes or so. Also when it's not booting I can see that a little red light comes on on the logic board behind the cpu's.

Anyways I'm thinking it may be a power supply issue but if any experts wanna help me out with some advice I'd be very grateful.

Thanks in advance,


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Will it boot in target mode (firewire cable to the laptop and holding the "T" key on the Pro)?


Well Today I tried using a pci video card from a g5 xserve and it exhibited the same behavior so now I know it's not the agp slot.

When it has the cards in it won't do anything except make the bong and the fans come on and then after a minute or so a red light comes on behind the processor and the fans start revving up super loud. At first it would display up till the grey apple stage of the boot sequence and then hang.Now the display does not come on at all.when it is doing this the machine will not respond to any keystrokes etc. so no target disk. when i pull the cards out all is normal and i can boot into target disk ,safe boot,whatever except i need to connect to it via remote desktop to see anything.Like this the machine is stable and will run normally.I also tried disconnecting the optical drive and hard drives to see if that helped but it didn't .

Of course I have reset Pram and the pmu also.


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This can be due to a Northbridge problem, or simply need a PRAM and PMU reset.

The first thing to try is to reset the PMU. Refer to this picture as a reference. Hold the button in for 30 seconds. Follow this article for PMU reset instructions. SMC is Intel only with Macs.

To reset the PRAM on the system, shut the system down. Once you do this, hold Command+Option+P+R and then it will reboot. Hold this for 30 seconds or until the system reboots and see what happens.

If this doesn't fix the problem, it's the RAM, power supply or motherboard. However, some of these are due to a dead PRAM battery. Most of them seem to have bad motherboards, but it may not hurt to try new RAM and see if the problem clears up. You can try the power supply if you want, but this part is very hard to find.

Here's the guide for the PRAM Battery, the guide for the RAM and a guide for the motherboard.

Power Mac G5 PRAM Battery Image


Power Mac G5 PRAM Battery Replacement


Very easy

2 minutes

Power Mac G5 RAM Image


Power Mac G5 RAM Replacement



10 - 15 minutes

Power Mac G5 Motherboard Image


Disassembling Power Mac G5 Motherboard



30 - 40 minutes

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