Replacing the power supply requires five basic steps:
1. Turn off the computer.
2. Open the computer.
3. Remove the installed power supply.
4. Install the replacement power supply.
5. Close the computer.
Note: HTML/QuickTime video versions of the instructions are available at http://www.info.apple.com/installparts.
Tools Required
The following tools are required for this procedure:
- Phillips screwdriver
- Allen wrench
Electrostatic Discharge (ESD)
Static electricity, a normal and natural phenomenon, builds up on your body as you walk around. You experience an electrostatic discharge (ESD) when you touch an object and feel a spark. ESD can cause damage to the internal components of your computer. Avoid walking around while performing this procedure, and follow the instructions carefully when you are asked to discharge static electricity.
Opening the Computer
Warning: Always turn off your computer before opening it to avoid damaging its internal components.
1. Place your computer on a clean, flat surface.
2. If you think your computer is in sleep, press the power button on the front of the computer to wake it.
3. Shut down your computer by opening the Special menu and choosing Shut Down. Then wait five minutes for the computer's internal components to cool down.
4. If you attached a security cable through the computer's lockable cover latch, remove the cable.
5. Unplug all other cables from the computer except the power cord.
6. Touch the metal PCI access covers on the back of the computer.
Important: To avoid electrostatic discharge, always ground yourself by touching the port access covers before you touch any parts or install any components inside the computer. To avoid static electricity building back up in your body, do not walk around the room until you have completed your installation and closed the computer.
7. Unplug the power cord.
8. Lift the latch on the right side access panel.
9. Gently lower the access panel until it lies flat. To avoid scratching the case, lower the panel onto a soft, clean cloth.
Warning: If you see any lights glowing on the main logic board, the computer has not been shut down. Close the side access panel and shut down the computer before proceeding.
Removing the Installed Power Supply
1. From inside the computer, push the CD/DVD/Zip bezel tabs forward to release the bezel from the front panel.
2. Disconnect the bezel from the slots on the left side of the front panel and remove the bezel from the computer.
3. Remove the two screws on the drive carrier.
4. Move the CD/DVD/Zip drive carrier forward 1 inch.
5. Disconnect the power-to-fan connector.
6. Disconnect the following power cables:
- cables P6 and P7 from the CD/DVD and Zip drives (if installed)
- main power cable from the logic board
- power cable(s) from any hard drives
7. Using a 2.5 mm Allen wrench, remove the three screws on the rear vented panel.
8. Remove the Phillips screw that attaches the power supply to the power supply shelf.
9. If the opening for the cables in the power supply shelf extends across the width of the shelf, slide the power supply toward the front of the computer. Then maneuver the power supply and its cables out of the computer.
10. If the opening in the power supply shelf does not extend across the width of the shelf, remove the two screws that attach the fan bracket to the chassis.
11. Pull the bracket straight down to release it from the two holding tabs on the underside of the shelf, and remove the bracket from the computer.
12. Slide the power supply toward the front of the computer. Then maneuver the power supply and its cables out of the chassis.
Installing the Replacement Power Supply
1. Transfer the power supply bracket from the original power supply to the new power supply.
2. Position the new power supply in the power supply shelf and thread the main and hard drive power cables through the opening in the shelf.
3. If you removed the fan bracket, reinstall it and the two mounting screws. Make sure the slots in the top of the bracket engage with the two holding tabs on the underside of the power supply shelf. Otherwise, the screws that attach the bracket to the chassis will not align properly.
4. Reinstall the three Allen screws on the rear panel.
5. Reconnect the following power cables:
- cables P6 and P7 to the CD/DVD and Zip drives
- main power cable to the logic board
- power cable(s) to any hard drives
6. Reconnect the power-to-fan connector.
7. Move the CD/DVD/Zip drive carrier back so the carrier front is flush with the front panel.
8. Reinstall the two drive carrier mounting screws.
9. Position the CD/DVD/Zip bezel in the slots in the left side of the front panel, insert the bezel tabs into the slots on the right side of the panel, and snap the bezel into place.
Replacement Note: To avoid damaging the computer, make sure the power supply voltage switch is on the correct setting (115 V in US).
Closing the Computer
1. Raise the side access panel, lift the latch, and press the panel against the case until it snaps securely into place.
2. Reconnect all cables and restart your computer.
Warning: Never turn on your computer unless all of its internal and external parts are in place and it is closed. Operating the computer when it is open or missing parts can damage your computer or cause injury.