Apple iMac G5 20 Ambient Light Sensor Service Manual



Service Source

iMac G5, 20-inch (Ambient Light

Sensor)

Updated 1 October 2007

iMac G5, 20-inch (Ambient Light Sensor)

iMac G5, 20-inch -



Service Source

Take Apart

iMac G5, 20-inch, Ambient Light

Sensor

General Information

What’s New

October 2007

Updated Logic Board replacement procedure. A “caution” was added to notify service providers not to twist, ﬂex, or bend the iMac G5 logic as you install to board into the chassis. Flexing the board may jeopardize the thermal interface between the heatsink and the processor. Refer to the iMac logic board inbox notice 073-1158 for additional information.

November 2006

On November 2, 2006, Apple announced the iMac G5 Repair Extension Program (REP) for Power Supply Issues. Information on the Repair Extension Program for Power Supply Issues has been added to the take apart and troubleshooting chapters.

This REP is a worldwide program that applies to iMac G5 20-inch (Ambient Light Sensor) models sold worldwide between May 2005 and October 2005 that feature a 2.0GHz G5 processor and that have power-related issues as a result of a speciﬁc component failure within the computer's power supply. Refer to the “iMac G5 Repair Extension Program (REP) for Power Supply Issues” document at the begining of the manual for more information.

Note

July 2006

A diecut piece of microfoam (922-7671) is included with all replacement optical drives and display bezels. It should be installed in between the disc drive and the display bezel to prevent optical media from ejecting out of the system and dropping to the desktop. Only one diecut of microfoam should be used per system. Refer to the replacement procedures in Take Apart for either the optical drive, display bezel, or microfoam shim for more information.

Display/Bezel Assembly Elimination

Effective July 24, 2006, the Display and Bezel assembly module will no longer be available as a single service part for the iMac G5 (17- and 20-inch models). The Display and Bezel are now available as two separate service parts (see below) to simplify inventory and

General Information

: The iMac G5 power supply is no longer available as a Do-It-Yourself (DIY) part.

iMac G5, 20-inch, Ambient Light Sensor Take Apart -

reduce repair costs.

• 922-6817 Front Cover Assy,w/Optical Slot, iMac G5 20"

• 661-3622 Panel, Display w/Brackets, iMac G5 20"

Tools Required

The following tools are required to service the computer:

• Phillips #2 screwdriver

• Phillips #1 screwdriver

• Flat-blade screwdriver

• Torx T6, T8, and T10 screwdriver

• Jeweler’s flat-blade screwdriver

• Nylon probe tool (black stick 922-5065)

• Needlenose pliers

• Soft cloth (to protect removed parts from scratches)

New Procedures and Service Parts (May 2005)

• Fans, Upper

• Fan, Lower

• Logic board

• Speakers

• Microphone

• AirPort/Bluetooth card

• Modem

• Chassis

• Antennas

• LED light pipe

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General Information

Important Things to Know

1. These instructions cover the iMac G5, 20-inch, Ambient Light Sensor model; however, the procedures from the original 20-inch model are very similar. In some steps graphics from the original model may be used.

2. All customer removable screws are brass colored (except for some fan screws on earlier units which use torx screws). Do not remove screws unless they are brass colored, or you will void your warranty.

3. Ground yourself when working on the computer. The procedure will show you how to ground yourself.

4. A magnetized “L”-shaped Phillips screwdriver is included with the replacement part.

5. The following items are no longer offered as a Do-it-Yourself repair:

• midplane

• display/bezel

• power supply

6. Additional items are included with these service parts.

Back Cover

• Two blank labels are included with the replacement back cover. Copy the serial

number and Ethernet number off the bottom of the computer’s foot and attach the new labels to the bottom of the replacement foot. The back cover take apart procedure will show you where to attach the labels.

Logic Board

• The LED gasket and light pipe are included

• Syringe with thermal compound

• Alcohol cleaning wipe

• A new pre-printed Ethernet label is included with the midplane. Attach the sticker to

the bottom of the computer’s foot, above the existing label.

• A blank serial number label is included with the midplane. Copy the serial number

off the bottom of the computer’s foot and attach the new label to the midplane. The midplane take apart procedure will show you where to attach the label.

7. Do not pull on individual wires when disconnecting a part; pull on the connector.

8. A screw chart is attached at the end of this document. Use the chart to identify screw type and screw locations.

General Information

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Ambient Light Sensor

The new iMac G5 has an ambient light sensor. It’s located on the bottom of the display bezel, near the case screws. Look at the picture below. Next to the middle screw is a small bump protruding from the case. This is the ambient light sensor.

The ambient light sensor attaches to the power supply with two plastic rivets.

The ambient light sensor cable runs under the power supply and attaches to the logic board.

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iMac G5, 20-inch, Ambient Light Sensor Take

General Information

Removing the Back Cover

Tools Required

The only tool required is a Phillips #2 screwdriver

Part Location

Removing the Back Cover

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Procedure

1. Turn your computer off by choosing Shut down from the Apple (K) menu.

2. Disconnect all cables, and unplug the power cord from your computer. Put on your ESD Wrist strap.

3. Place a soft, clean towel or cloth on the desk or surface. Hold the sides of the computer and slowly lay the computer face down as shown.

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iMac G5, 20-inch, Ambient Light Sensor Take

Removing the Back Cover

4. Locate the three silver case screws circled below. You may have to lift the stand to locate the middle case screw. display/bezel assembly and cannot be removed.

Using a Phillips #2 screwdriver, loosen the three captive screws. Turn the screws to the left until they stop turning.

Note:

These screws are captive; they are part of the

Don’t force the screws once they stop turning.

5. Holding the back cover by the metal foot, tilt the cover up and lift it off the computer. Set the back cover aside.

Removing the Back Cover

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Replacing the Back Cover

Tools Required

The only tool required is a Phillips #2 screwdriver.

Procedure

1. Remove the replacement back cover and foot from its packaging.

2. Replace the cover so that the slots on the top edge of the back cover mate with the tabs on the display housing.

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iMac G5, 20-inch, Ambient Light Sensor Take

Replacing the Back Cover

3. Lower and press the cover into place until it ﬁts snugly on the computer.

4. Tighten the case screws by turning them to the right.

Replacing the Back Cover

iMac G5, 20-inch, Ambient Light Sensor Take Apart -

5. Position the computer in the upright position. Reconnect the power cord and remaining cables. Power on the computer.

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iMac G5, 20-inch, Ambient Light Sensor Take

Replacing the Back Cover

Grounding Yourself

Tools Required

• Phillips #2 screwdriver, preferably with a magnetized tip

Preliminary Steps

Before you begin, remove the back cover.

Grounding Yourself

1. Touch the metal surface (as shown below) on the inside of the computer to discharge any static electricity.

Warning: Always discharge static electricity before you touch any parts or install any components inside the computer. To avoid generating static electricity, do not walk around the room until you have ﬁnished installing the part and closed the computer

Grounding Yourself

iMac G5, 20-inch, Ambient Light Sensor Take Apart -

Hard Drive

Tools Required

• Phillips #2 screwdriver, preferably with a magnetized tip

• Needlenose pliers

• Screw tray or equivalent to hold the screws

Preliminary Steps

Before you begin, remove the back cover.

Part Location

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iMac G5, 20-inch, Ambient Light Sensor Take

Hard Drive

Removing the Serial ATA Hard Drive

1. Remove the three hard drive screws. Set the screws aside.

2. Lift the hard drive straight up, about one inch, to access the connector shown below. Disconnect the black connector from the side of the hard drive. disconnect the other end of the cable from the board.

Note:

Do not

Hard Drive

iMac G5, 20-inch, Ambient Light Sensor Take Apart -

3. Using your ﬁngers, disconnect the drive data cable and power cable from the hard drive. Lift the hard drive up and out of the midplane assembly. hard drive to Apple in the packaging provided.

Important:

Return this

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iMac G5, 20-inch, Ambient Light Sensor Take

Hard Drive

Replacing the Serial ATA Hard Drive

1. Remove the replacement hard drive from its packaging.

2. Connect the drive data cable and power cable to the hard drive. Lower the hard drive into place on the midplane.

3. Connect the hard drive thermal sensor to the sensor board on the side of the hard drive.

Hard Drive

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4. Replace the three hard drive screws.

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iMac G5, 20-inch, Ambient Light Sensor Take

Hard Drive

Optical Drive

Tools Required

• Phillips #2 screwdriver, preferably with a magnetized tip

• Screw tray or equivalent to hold the screws

Preliminary Steps

Before you begin, remove the back cover.

Part Location

Optical Drive

iMac G5, 20-inch, Ambient Light Sensor Take Apart -

Removing the Optical Drive

1. Using a Phillips #2 screwdriver, remove the four optical drive screws circled below. Set the screws aside.

2. Pull the optical drive tab straight up and then to the right. Set the optical drive aside.

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iMac G5, 20-inch, Ambient Light Sensor Take

Optical Drive

Replacing the Optical Drive

Note:

A microfoam insert is included with the replacement optical drive and should be installed using the instructions included below. The microfoam insert will prevent optical media from ejecting out of the system and dropping to the desktop. Only one microfoam insert should be used per system

2. Locate the enclosed piece of white microfoam and the two white posts (circled) on the bezel.

3. With the shiny side of the microfoam facing the bezel, slide the holes of the microfoam onto the two white posts on the bezel.

Optical Drive

iMac G5, 20-inch, Ambient Light Sensor Take Apart -

4. Tuck the mircofoam into place before installing the optical drive.

5. Remove the replacement optical drive from its packaging.

6. Slide the optical drive into the display bezel and press down near the tab to reconnect the drive.

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iMac G5, 20-inch, Ambient Light Sensor Take

Optical Drive

7. Replace the four optical drive screws. Replace the back cover. Return the optical drive to Apple in the packaging provided.

8. Replace the back cover.

9. Make sure no microfoam is sticking out of the bezel. computer, partially insert an optical disc to make sure it inserts smoothly.

Note:

Before reassembling the

Optical Drive

iMac G5, 20-inch, Ambient Light Sensor Take Apart -

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iMac G5, 20-inch, Ambient Light Sensor Take

Optical Drive

Microfoam Shim

Tools Required

• Use the screwdriver provided, or a Phillips #2 screwdriver, preferably with a

magnetized tip

• Screw tray or equivalent to hold the screws

Preliminary Steps

Before you begin, remove the back cover and the optical drive.

Part Location

Microfoam Shim

iMac G5, 20-inch, Ambient Light Sensor Take Apart -

Installing the Microfoam onto the Bezel

1. Locate the piece of microfoam and the two white posts (circled) on the bezel.

2. With the shiny side of the microfoam facing the bezel, slide the holes of the microfoam onto the two white posts on the bezel.

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iMac G5, 20-inch, Ambient Light Sensor Take

Microfoam Shim

3. Tuck the mircofoam into place before installing the optical drive.

4. Replace the optical drive in the direction of the arrow, lining up the white posts on the bezel with the holes on the optical drive bezel.

Microfoam Shim

iMac G5, 20-inch, Ambient Light Sensor Take Apart -

5. Slide the optical drive into place and press down near the tab to reconnect the drive.

6. Make sure no microfoam is sticking out of the bezel. computer, partially insert an optical disc to make sure it inserts smoothly.

Note:

Before reassembling the

7. Replace the optical drive screws.

8. Replace the back cover.

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iMac G5, 20-inch, Ambient Light Sensor Take

Microfoam Shim

Inverter

Tools Required

• Phillips #2, preferably with a magnetized tip

• Needlenose pliers

• Screw tray or equivalent to hold the screw

Preliminary Steps

Before you begin, remove the back cover.

Part Location

Inverter

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