Power Mac G5 Power Supply Replacement

Student-Created Guide

Student-Created Guide

An awesome student from our education program made this guide. It is not managed by iFixit staff.

  • Author: Adam
  • Difficulty: Moderate

This guide will detail how to remove the Apple G5's main power supply.

Image #1

Edit Step 1 Side Panel  ¶ 

  • To avoid electrocution, shut down the computer. Do not open the computer or attempt to install any items inside it while the computer is on.

  • To avoid being shocked, wait at least 10 minutes to allow the computer's internal components to cool.

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Edit Step 2  ¶ 

  • Remove all the cables, including the power cables before opening the unit.

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Edit Step 3  ¶ 

  • Lift the tab to unlock the side panel.

  • The panel should fall out. If the panel does not fall out by itself pull a little from the edges.

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Edit Step 4  ¶ 

  • Remove the air deflector (the clear plastic cover) by pulling on the handle.

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Edit Step 5 Front Fan Assembly  ¶ 

  • Locate the front fan assembly.

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Edit Step 6  ¶ 

  • Pull the fan assembly out; it should slide out easily.

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Edit Step 7 Bottom Right Cooling Fan Unit  ¶ 

  • The cooling fan unit is located on the bottom right of the Apple G5 Desktop.

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Edit Step 8  ¶ 

  • Remove the G5 metal cover from the processing/cooling unit of the computer. NOTE: Apple inserted a rather fragile plastic pin that inserts through the top divider shield and clips into a tab on the hidden ledge of this CPU shield. Removing this pin, certainly voided Mac's warranty - but more appropriate for now, voids most after-market insurance plans. A replacement pin (new) is hard to get ahold of, and very few are talented and patient enough to remove this pin without damaging it. Just something to keep in mind. If you have no warranty any longer or don't care, please continue...

  • Pull the metal plate to the left and outward to remove the plate from the processing/cooling unit.

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Edit Step 9  ¶ 

  • Locate the bottom right fan.

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Edit Step 10  ¶ 

  • Unplug the fan's power cable from the upper rightmost corner of the motherboard (connection J45). If there is a video card in place, carefully pull the cable plug down between the back edge of the video card and the motherboard. Note, the photo shows the unplugged cable and the area it plugs into outlined in yellow. No video card is shown in this photo.

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Edit Step 11  ¶ 

  • Locate the tabs on the fan unit.

  • While pushing in on the tabs, highlighted in yellow, pull the fan back towards the cooling unit.

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Edit Step 12  ¶ 

  • After the latches are out, pull the fan out.

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Edit Step 13  ¶ 

  • After removal of the bottom right fan the space should look like this.

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Edit Step 14 Processor and Cooling Unit  ¶ 

  • Locate the Cooling Unit on the Apple G5.

  • Put the CPU case on its back with the opening facing up to make the next steps easier.

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Edit Step 15  ¶ 

  • Unscrew 8 T10 screws from the cooling unit. NOTE: these screws are acctually allen keys. The prefered tool will be long handled allen keys. t10 are 2.74mm (closest allen key is 2.5 or 3mm) and t15 are 3.27mm(closest allen key is 3mm and 4mm). You may strip your tool or the actual screws themselves. Use a set of high quality long handled allen keys.

  • The screws are somewhat hidden, so they cannot be see in the picture.

  • To visualize the location of the screws look 3 steps ahead.

  • The screws will loosen but will not come out, they are designed to loosen the unit, but remain in place.

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Edit Step 16  ¶ 

  • Pull the cooling/processing unit straight up to prevent damage to logic board

  • This will require some effort and should be done with caution to avoid damage.

  • The sleeves around the 6 screws may hold it in, if so just take a pair of needle nose pliers and gently squeeze the sleeves until it releases.

  • Pull the bottom, then side towards the bottom of the CPU case, first to move around the bottom coolant sleeve around the heat sinking bracket. *heat sinking bracket not in picture*

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Edit Step 17  ¶ 

  • Disconnect the cable.

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Edit Step 18  ¶ 

  • NOTE: Here are the standoffs without the cooling unit installed to make it easier to understand where the screws are located. Remove the bottom 2 standoffs so it is easier to remove the power supply.

  • Check the pin connections for any damage. All the pins highlighted in yellow should appear straight up and not appear bent. DON'T TOUCH THE PINS. A bent pin will result in your computer not powering on.

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Edit Step 19 Power Supply  ¶ 

  • Locate the power supply in the Apple G5 computer. It is located under the metal plate at the bottom of the computer case.

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Edit Step 20  ¶ 

  • Undo the clip shown by pulling up on the edge closest to the RAM slots.

  • Unplug the black rectangular plug with a rounded top by pulling outwards.

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Edit Step 21  ¶ 

  • Undo the clip shown by pulling up on the edge.

  • Unplug the cord that is located below where the cooling unit was. To do this, pull outwards.

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Edit Step 22  ¶ 

  • Remove the 2 Philips screws holding the power supply cover on.

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Edit Step 23  ¶ 

  • Remove the power supply cover.

  • This will require some bending, be sure not to bend the metal too much to prevent damage to the metal

  • Pull the metal cover up slightly and out of the computer to prevent damage to the logic board.

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Edit Step 24  ¶ 

  • Remove the 4 Philips screws on the underside of the computer case.

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Edit Step 25  ¶ 

  • Carefully pull the power supply out of the case.

  • Do not completely remove the power supply since it is still attached to a cable.

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Edit Step 26  ¶ 

  • Unplug the final cable attached to the power supply from the computer.

  • Now the power supply should come out of the computer freely.

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Edit Step 27  ¶ 

  • The bottom of the computer should look like this when removal of the power supply is complete.

To reassemble your device, follow these instructions in reverse order.

For more information, check out the Power Mac G5 device page.

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Comments Comments are onturn off

Swap the Power Supply from G5 2.0 Dual 2004.

lunchbx2, · Reply

Step #16 is kinda confusing on the last paragraph. Can anyone clarify.? Thanks.

Danno, · Reply

I followed this guide to replace the PSU in my 2x2.0 PCI G5 - it now works great. I'd like to add that my machine didn't boot right away, I needed to reset the SMU on the main Logic board several times and I also re-seated the RAM chips which seemed to cajole the old beast back into life. I replaced a 450W PSU with a 600W and all seems well so far. Many thanks to the team for posting this ifixit guide.

Chris Allen, · Reply

these Apple support notes are worth a look if you run into problems restarting a machine:




Chris Allen, · Reply

Finally - I would also like to add that this guide shows the CPU unit of what I think is one of the crazy liquid-cooled G5s that made a brief appearance in the Powermac range. The same steps still apply for the more common air-cooled models. The only difference being that my machine's CPU units were secured on their mountings with Allen-key type screws - not Torx screws. Doing this repair was not as difficult as you might think, I managed fine and I'm not a tech specialist.

Chris Allen, · Reply

The quad core G5 that I have in the UK requires the logic board to be removed before the power supply can be accessed.

Andrew Hinton, · Reply

maybe you can replace the pin and get away with it

Nick, · Reply

The whole pin assembly acts like a miniature toggle bolt. The inner part of the pin assembly is actually a short stubby cylinder. When the pin is inserted into the sleeve, it presses on the sleeve and expands it slightly in the processor shield, locking it to the top divider shield.

I took a tiny drill bit and spun it into the center of the pin just enough so that I could insert a small sharp screw (I used a cup hook) into the pin. All it needed was just a slight tug, and the pin came out of the outer locking sleeve. I used the same screw to remove the outer sleeve.

Steve, · Reply

Before pulling fan, you must unplug fan power cable from upper right-most corner of mother board (connection J45). Carefully pull cable down past the video card's back-side.

Sam Taylor, · Reply

Thank you for this mention. It seems important, do you have a snapshot of it?

Is it hard to find/reach?

And plugging it back in with the new one, any problems?



that looks completely different and I can't unscrew it :/

grze, · Reply

Very difficult on some models.

Nate Aguilar, · Reply

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