Apple eMac 02 Service Manual

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Service Source

eMac

© 2002 Apple Computer, Inc. All rights reserved.

eMac

eMac -

1

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Service Source

Take Apart

eMac

© 2002 Apple Computer, Inc. All rights reserved.

Tools

The following tools are recommended for the take apart procedures.

• 2.5 mm hex (for rear housing)

• phillips #2 screwdriver

• jeweler’s screwdriver set

• needlenose pliers

• ESD wriststrap and mat

• CRT discharge tool

Note:

Do not use a power driver on the rear housing screws.

Tools

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CRT Neck/Display/Analog Assembly Handling Information

Handling

Important:

when working with the display/analog assembly.

Do NOT lift, handle, bump, or manipulate the CRT neck/neck board (see red arrows
below) on the Display/Analog assembly. Modules damaged by mishandling are NOT
covered by Apple Warranty. Apple Authorized Service Providers can be liable for broken
CRT necks due to improper handling.

Caution

handling the assembly. Lift the assembly from the metal chassis; never lift the assembly
from the neck. I

It is imperative that proper handling and packaging guidelines be followed

: The metal chassis has sharp edges, you may want to wear gloves when

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Packing a Defective Display/Analog Assembly

The packing procedure is included with the replacement display/analog assembly.
Incorrect packaging can result in damaged eMac displays. Please read and follow the
directions enclosed in the shipping box of the new display prior to packaging the defective
assembly. AASPs can be liable for broken CRT necks due to improper packing and
handling.

CRT Neck/Display/Analog Assembly Handling Infor-

User Access Door

Tools

This procedure requires the following tools:

• Phillips #2 screwdriver

Part Location

User Access Door

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

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Procedure

1. Remove the screw on the user access door

2. Gently remove the access door.

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User Access Door

Feet

Tools

This procedure requires the following tools:

• Phillips #2 screwdriver

Part Location

Feet

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

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Procedure

1. Remove the two screws. Set the plastic feet aside.

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Feet

Rear Housing

Tools

• 2.5 mm hex.

Part Location

Rear Housing

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the feet.

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Procedure

1. Remove three screws located below the user access door (these three screws are
longer that the rest of the rear housing screws).

2. Remove the six remaining rear housing screws.

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Rear Housing

3. Gently lift the rear housing up about 2 inches.
the power button (on the inside of the housing) can become permanently damaged or
the machine may not power on.

Warning:

If you lift the housing too fast,

4. Carefully disconnect the power cable from the power button located inside the rear
housing. Lift the rear housing off the computer.

Rear Housing

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Power Button

Tools

• needlenose pliers

•

Note:

Follow this take-apart procedure only if you are replacing a defective power

button.

Part Location

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eMac Take Apart

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the feet.

• Remove the rear housing.

Power Button

Procedure

1. Disconnect the power cable from the power button located inside the rear housing. Lift
the rear housing off the computer.

2.

Note:

Continue with this procedure only if you are replacing a defective power button.
With a needlenose pliers, push the power button through the retaining ring. The power
button will pop off rear housing and the retaining ring may get stuck on the pliers.

Power Button

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3. Save the retaining ring (shown below)

4.

Replacement Note:

power button. Position the power button into the hole on the rear housing (as shown
below).
rear housing.

Note:

The picture below is looking at the power button from the inside of the

Obtain a new power button and peel the sticky backing off the

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5. Place the retaining ring over the power button connector and press down firmly.

Power Button

CRT Discharge

Warning:

injury, always review the Service Foundations: CRT Displays course for safety information.
It can be found at: http://service.info.apple.com/service_training/training.html. Click on
Desktop Certification Courses and select the Service Foundations: CRT Displays link.

Warning:

an ongoing ground connection.

This product contains high voltage and a high-vacuum picture tube. To prevent

Never use a grounding wriststrap until after discharging the CRT and setting up

Safety Guidelines:

Whenever the rear housing of the computer is removed and before replacing a module,
you must

1. Discharge the CRT (shown below) and remove the anode cap.

CRT Discharge

2. Establish an ongoing ground by using a cable with alligator clips at both ends.
Connect one end to the anode aperture, and connect the other end to the metal CRT
frame (as shown below).

3. With the CRT discharged and the ongoing ground in place wear a grounding
wriststrap to prevent equipment damage from static electricity.

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Speakers

Tools

This procedure requires the following tools:

• Jeweler’s #1 screwdriver (for removing metal plate on speaker assembly)

Part Location

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eMac Take Apart

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

Speakers

Procedure

1.

Note:

The speaker assembly is not screwed down. Gently pull the speaker assembly

in the direction of the arrow.

2. Disconnect the speaker cable on the left side. Lift the speaker assembly out of the
computer.

Speakers

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Fan

Tools

This procedure requires the following tools:

• Phillips #2

Part Location

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eMac Take Apart

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

Fan

Procedure

1. With the fan facing you, disconnect the two circled screws and disconnect the fan
cable.

2. On the right side of the fan, remove two screws (one of which is the ground screw),
and disconnect the fan power cable

.

Fan

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3. To locate the last fan screw, turn the computer so the anode socket is facing you. You’ll
see two screws. Remove the top screw.

4. To remove the fan, turn the computer so the fan is facing you. Grab onto the fan near
the AC plug and the bottom right corner of the fan. Gently pull the fan toward you and
away from the chassis. Be very careful of the CRT neck.

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Fan

Faraday Cage

Tools

This procedure requires the following tools:

• Phillips #2

Part Location

Faraday Cage

Preliminary Steps

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

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Procedure

1. Remove the five screws.
cage so it doesn’t get caught when you remove the Faraday cage.

Important:

Push the power button cable inside the Faraday

2. Gently pry the Faraday cage away from the chassis in the direction of the arrows.

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Faraday Cage

Digital Module Assembly

Tools

This procedure requires the following tools:

• Phillips #2

Part Location

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

Digital Module Assembly

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• Remove the fan.

• Remove the Faraday cage.

• Remove the AirPort Card if installed.

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Digital Module Assembly

Procedure

1. With the digital module facing you, remove the four screws on the left side of the digital
module.

2. Next, remove the three screws on the right side.

Digital Module Assembly

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3. On the top right side of the digital module, remove one screw.

4. On the top left side of the digital module, remove one screw.

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Digital Module Assembly

5. Remove one screw on the I/O panel and disconnect the video cable located above the
screw. Squeeze the tabs to disconnect the video cable.

6.

Note:

Remove the AirPort card if it’s installed. Grab onto the digital module at the tabs
circled below. Pull in the direction of arrow. The digital module is connected to blind­mate connectors. It’s a tight fit, so pull hard.

Digital Module Assembly

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IVAD Cable

Important: Take Apart Note: Replace the IVAD cable if the eMac raster shifts upward
from the bottom of the display or the raster is jumpy, otherwise leave the cable alone.
Refer to Knowledge Base article 95168 for more information.

Tools

This procedure requires the following tools:

• 2.5 mm hex tool

• Phillips #2 screwdriver

• Hot-melt glue gun (recommended)

• Nylon probe tool (922-5065)

Procedure

1. Remove the rear housing from the eMac.

Discharge the CRT. Warning: This product contains high voltage and a high-vacuum

2.

picture tube. To prevent injury, review the Service Foundations course: “CRT Displays”
for safety information.

3. Locate the IVAD assembly shown below.

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IVAD Cable

4. Note: The screws on IVAD assembly need to be removed to access one end of the
IVAD cable. Remove the screw (circled below) and then remove the metal
cable cover.

5. Remove the remaining two screws on the IVAD assembly.

IVAD Cable

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6. With the nylon probe tool or needlenose pliers, remove the glue from the
connector.

Note: If you find it difficult removing the glue use a heat gun to

soften the glue a bit and then remove it. Disconnect the cable after removing
the glue.

7. Locate the other end of the IVAD cable.

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IVAD Cable

8. With the nylon probe tool or needlenose pliers, remove the glue from the

cable connector.

Note: If you find it difficult removing the glue use a heat gun

to soften the glue a bit and then remove it.

9. Clip the cable tie. Disconnect the IVAD cable from the board.

IVAD Cable

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IVAD Cable Replacement Procedure

1. Install the replacement IVAD cable.

2. Replace the cable tie (shown on the previous page).

3. Place hot glue on each end of the IVAD connector.

4. Reassemble the computer and test the system.

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IVAD Cable

AirPort Card Guide

Tools

This procedure requires the following tools:

• Phillips #2

Part Location

AirPort Card Guide

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

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• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

• Remove the digital module assembly.

Procedure

1. Remove the two screws connecting the guide to the chassis.

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AirPort Card Guide

2. Lift the AirPort card guide in the direction of the arrow to unhook the metal tabs
(circled) on the chassis. Disconnect the antenna from the AirPort card guide Note:
Tape the antenna to the bottom of the unit while in for service.

AirPort Card Guide

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LED

Tools

This procedure requires the following tools:

• Phillips #2

Part Location

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

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LED

• Remove the fan.

• Remove the Faraday cage.

• Remove the digital module assembly.

Procedure

1. Remove one screw and disconnect the LED cable. Important: The connector is very
fragile, remove it gently. Lift the LED board off the LED reflector.

LED

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2. Note: The LED consists of two parts; the LED board and the LED reflector (black
plastic piece shown below). Remove the LED reflector from the bezel.

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LED

Front Bezel

Tools

This procedure requires the following tools:

• Phillips #2

Part Location

Front Bezel

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

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• Remove the Faraday cage.

• Remove the digital module assembly.

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Front Bezel

Procedure

1. Remove the eight bezel screws. There are three on each side and two at the top of the
bezel.

2. Important: DO NOT remove the two larger screws shown below, or the two screws
shown in the next photo. DO NOT remove these larger screws. If they are removed,
the CRT will be out of alignment and the entire display/analog assembly will need to
be replaced.

Front Bezel

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3. Do Not remove these CRT screws either.

4. Disconnect the microphone cable.

5. Carefully lift the display/analog assembly off the bezel.

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Front Bezel

Antenna Board

Tools

This procedure requires the following tools:

• Phillips #2 screwdriver

• Needlenose pliers

Part Location

Antenna Board

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

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• Remove the front bezel.

• Remove the digital module assembly.

Procedure

1. Remove one screw and pinch the standoff with a needlenose pliers to release the
antenna board from the divider panel.

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Antenna Board

2. Carefully position the computer on it’s base. Facing the CRT, locate the metal antenna
bracket at the top of the CRT. Remove the screw attached to the bracket.

3. Carefully pry the antenna cable from the two clips on the side of the CRT.

Antenna Board

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Microphone

Tools

This procedure requires the following tools:

• Phillips #2

Part Location

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

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Microphone

• Remove the Faraday cage.

• Remove the digital module assembly.

• Remove the front bezel.

Procedure

1. Remove the microphone cable from the bezel. Replacement Note: When replacing
the microphone into the bezel, the metal faces down, the dimple faces up.

Microphone

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Down Converter

Tools

This procedure requires the following tools:

• Phillips #2

Part Location

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

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Down Converter

Procedure

1. With the down converter still attached to the digital module, remove the screw shown
below.

2. Looking at the digital module from the back, remove the second screw.

Down Converter

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3. Disconnect the down converter from the logic board by holding the board at the top
and the bottom and gently rock the board in the direction of the arrow.

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Down Converter

Door Assembly

Tools

This procedure requires the following tools:

• Phillips #2

Part Location

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

Door Assembly

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• Remove the Faraday cage.

• Remove the digital module assembly.

Procedure

1. Remove the two screws connecting the door to the front bezel.

2. Remove the door from the front bezel. Replacement Note: Transfer the serial number
label on the inside of the door to the replacement door.

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Door Assembly

Hard Drive

Tools

This procedure requires the following tools:

• Phillips #2

• Jeweler’s #1 screwdriver

Part Location

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

Hard Drive

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• Remove the fan.

• Remove the Faraday cage.

• Remove the digital module assembly.

Procedure

1. Remove the three screws along the back of the hard drive.

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Hard Drive

2. WIth a screwdriver or plastic tool, pry the hard drive out of the hard drive carrier to
access the power and data cables.

Hard Drive

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3. Disconnect the hard drive power cable and the hard drive data cable. Remove the
drive from the carrier. Notice the three thermal pads on the hard drive; two on the top
and one along the side of the drive. Replace the thermal pads if they are damaged.

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Hard Drive

4. Turn the hard drive over. WIth a jeweler’s screwdriver, remove the two screws on the
black plastic cover and the two screws on the metal bracket. Note: These two pieces
need to be removed when returning the hard drive to Apple service.

Hard Drive

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Hard Drive Carrier

Tools

This procedure requires the following tools:

• Phillips #2 screwdriver

Part Location

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

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Hard Drive Carrier

• Remove the Faraday cage.

• Remove the digital module assembly.

• Remove the hard drive.

Procedure

1. Remove the seven carrier screws. Peel back the EMI tape on the on both sides of the
carrier.

2. Lift the carrier off the logic board.

Hard Drive Carrier

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Logic Board Heatsink

Tools

This procedure requires the following tools:

• Screwdriver to pry the heatsink clip

Part Location

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

• Remove the digital module assembly.

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Logic Board Heatsink

• Remove the hard drive.

• Remove the hard drive carrier.

Procedure

1. With a screwdriver, pry the heatsink clip out of the hole on the logic board.

2. Lift the heatsink off the logic board. Replacement Note: Whenever the heatsink is
removed, the bottom side of the heatsink and the top of the microprocessor must be
cleaned and thermal paste must be applied to the microprocessor. If the mating
surfaces are not cleaned and thermal paste is not applied, the CPU may overheat and
become damaged. Refer to the next topic, “Thermal Paste Application”.

Logic Board Heatsink

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Thermal Paste Application

The microprocessor uses a heatsink/thermal pipe to transfer heat away. Whenever the
heatsink is removed, the bottom side of the heatsink and the top of the microprocessor
must be cleaned and thermal paste must be applied. If the mating surfaces are not
cleaned and thermal paste is not applied, the CPU may overheat and become damaged.

Tools

This procedure requires the following tools:

• Plastic stylus or nylon probe tool (922-5065) to remove the old thermal paste

• Thermal paste (922-4757), each tube contains 4-5 applications

Procedure

1. Thoroughly clean the thermal film from the heatsink surface with a plastic stylus or the
nylon probe tool. Do not use an abrasive material or liquid cleaner. Important: Be
extremely careful not to bend the heatpipes on the heatsink.

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Logic Board Heatsink

2. Carefully clean the surface of the microprocessor with a plastic stylus or nylon probe
tool (922-5065) to remove the old thermal paste.

3.

Squeeze a drop of thermal paste onto the middle of the microprocessor as
shown.

Logic Board Heatsink

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4. Spread the paste evenly over the processor. Important: On this product, it is critical

to spread the paste over the processor , or the chip could overheat.

5. Reinstall the heatsink and heatsink clip.

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Logic Board Heatsink

Logic Board

Tools

This procedure requires the following tools:

• Phillips #2 screwdriver

Part Location

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

Logic Board

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• Remove the digital module assembly.

• Remove the hard drive.

• Remove the down converter.

• Remove the hard drive carrier.

• Remove the logic board heatsink.

Procedure

1. Carefully position the assembly on the optical drive door. Disconnect the optical data
cable and the optical power cable.

64 eMac Take Apart

Logic Board

2. Turn the assembly so the logic board is facing up. Remove the four screws on the logic
board. Note: The screw in the bottom left corner is different from the other three
screws. It is self-tapping with no collar.

3. Lift the logic board off the optical assembly. Before returning the board to Apple,
remove the following items:

• I/O panel

• RJ-11 connector (if present)

• Modem board

• SDRAM

• Warning: The microprocessor uses a heatsink/thermal pipe to transfer heat away.

Whenever the heatsink is removed, the bottom side of the heatsink and the top of
the microprocessor must be cleaned and thermal paste must be applied to the
microprocessor. If the mating surfaces are not cleaned and thermal paste is not
applied, the CPU may overheat and become damaged. Refer to “Thermal Paste
Application” in this chapter.

Logic Board

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Memory

Tools

• No tools are required for this procedure

Part Location

Note: Memory can be accessed through the user access door on the back of the

computer.

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Unplug all cables except the power cord, from the computer.

• Remove the user access door.

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Memory

Procedure

1. Touch a metal surface inside the computer. Then unplug the computer. Important:
Always do this before you touch any parts, or remove/install any components inside
the computer. To avoid generating static electricity, do not walk around until you have
finished removing or installing the memory and closed the computer.

Memory

eMac Take Apart - 67

2. Locate the memory module.

3. Push the ejectors on the memory slot outward and down (#1) so they are in the open
position. Remove the memory module (#2). Replacement Note: The memory is
designed to fit into the slot only one way. Be sure to align the notches on the module
with the small notches inside the slot.

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Memory

Battery

Tools

• No tools are required for this procedure

Part Location

Note: The battery can be accessed through the user access door on the back of the
computer.

Battery

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Unplug all cables except the power cord, from the computer.

• Remove the user access door.

eMac Take Apart - 69

Procedure

1. Touch a metal surface inside the computer. Then unplug the computer. Important:
Always do this before you touch any parts, or remove/install any components inside
the computer. To avoid generating static electricity, do not walk around until you have
finished removing or installing the battery and closed the computer.

2. WIth a screwdriver or anti-static tool, carefully pry the battery out of the battery holder.

70 eMac Take Apart

Battery

I/O Panel

Tools

This procedure requires the following tools:

• Phillips #2 screwdriver

Part Location

I/O Panel

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

• Remove the digital module assembly.

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Procedure

1. Remove the two I/O panel screws.

2. Remove the I/O panel off the logic board.

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I/O Panel

Modem

Tools

This procedure requires the following tools:

• Phillips #1 or jeweler’s screwdriver

Part Location

Modem

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

• Remove the digital module assembly.

eMac Take Apart - 73

Procedure

1. Remove the two modem screws.

2. Disconnect the RJ-11 cable from the modem. Remove the modem.

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Modem

RJ-11 cable

Tools

No tools are required for this procedure

Part Location

RJ-11 cable

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

eMac Take Apart - 75

• Remove the digital module assembly.

• Remove the I/O panel

Procedure

1. Disconnect the RJ-11 cable from the modem.

2. With an anti-static tool, push and then pull the RJ-11 port off the logic board.

76 eMac Take Apart

RJ-11 cable

Optical Drive

Tools

This procedure requires the following tools:

• Phillips #2 screwdriver

Part Location

Optical Drive

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

• Remove the digital module assembly.

• Remove the hard drive.

• Remove the heatsink.

• Remove the logic board.

eMac Take Apart - 77

Procedure

1. Remove two screws on the right side of the optical carrier.

2. Remove two screws on the left side of the optical carrier.

78 eMac Take Apart

Optical Drive

3. Flip the optical carrier over and disconnect the optical power cable and the optical
data cable.

4. Remove the cotter pin (#1) from the carrier. Next, lift the heatshield by the metal fence
(#2), and lastly remove the heatshield in the direction of the arrow (#3) to detach it
from the carrier.

Optical Drive

eMac Take Apart - 79

5. Slide the optical drive out of the carrier by pushing it from the back end where the EMI
cap is located. Note: The EMI cap is not attached to the carrier or the optical drive.

80 eMac Take Apart

Optical Drive

Display/Analog Assembly

Tools

This procedure requires the following tools:

• No tools are required

Warning: This product contains high voltage and a high-vacuum picture tube. To prevent
injury, always review CRT Safety on Service Source online. This link can be found under
the list of topics under the iMac icon. Remember, never use a grounding wriststrap until
after discharging the CRT and setting up an ongoing ground connection.

Note: The eMac display/analog assembly requires no voltage calibration or geometry
adjustment. Should the display require adjustment (focus, color, or brightness) use the
“Displays” pane under System Preferences if using Mac OS X. If using Mac OS 9, use the
Monitor Control Panel to make adjustments. If you can not make satisfactory corrections
with these tools, replace the display/analog assembly.

Part Location

Display/Analog Assembly

eMac Take Apart - 81

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

• Remove the fan.

• Remove the Faraday cage.

• Remove the digital module assembly.

• Remove the AirPort card guide.

• Remove the front bezel

• Remove the antenna.

If you remove everything listed in the preliminary steps above, you are left with the display/
analog module. There is nothing more to remove from this module.

Note: The display/analog assembly contains a non-switching power supply which is preset
at a 220V configuration.The voltage selection needs to be manually set by the way of a
voltage jumper. This means if you are operating the computer in a 110V environment, you
will have to install the voltage jumper. Refer to the Troubleshooting chapter, “Digital/
Analog”

Replacement Note: If you are returning a defective display/analog module, it is imperative
that proper packaging guidelines be followed. The packing procedure is included with the
replacement assembly. Incorrect packaging can result in damaged eMac displays. Please
read and follow the directions enclosed in the shipping box of the new display prior to
packaging the defective module.

Failure to package the defective module according to the instructions may result in liability
for the cost of the damaged display.

82 eMac Take Apart

Display/Analog Assembly

LHR Coil

Tools

This procedure requires the following tools:

• Phillips #2 screwdriver

Part Location

Note: This part is used in Europe for line conditioning. If your computer does not have the
LHR, skip this procedure.

LHR Coil

Preliminary Steps

Before you begin, do the following:

• Place the computer face down on an ESD mat.

• Remove the user access door.

• Remove the feet.

• Remove the rear housing.

• Discharge the CRT.

eMac Take Apart - 83

Procedure

1. Remove the screw located at the bottom of the LHR module.

2. Disconnect the LHR connector located next to the fuse and to the right of the fan.

84 eMac Take Apart

LHR Coil

3. Disengage the tabs on the LHR. Note: The tabs (circled below) clip into the divider
panel. Remove the LHR from the divider panel.

LHR Coil

eMac Take Apart - 85

 Service Source

Troubleshooting

eMac

© 2002 Apple Computer, Inc. All rights reserved.

General Information

What’s New

1. Important: The display/analog assembly contains a non-switching power supply preset at a 220V
configuration. The voltage selection needs to be manually set by the way of a voltage jumper. If you are
operating the computer in a 110V environment, you will have to install the voltage jumper. Refer to
“Display/Analog Voltage Setting and LHR Module Instructions” discussed later in this chapter.
Note: The LHR coil (line conditioning module) is used in some international countries. Refer to the Take
Apart chapter, LHR topic, for take-apart information.

2. Important: If you are returning a defective display/analog assembly, it is imperative that proper
packaging guidelines be followed. The packing procedure is included with the replacement assembly.
Incorrect packaging can result in damaged eMac displays. Please read and follow the directions
enclosed in the shipping box of the new display prior to packaging the defective module.Failure to
package the defective module according to the instructions may result in liability for the cost of the
damaged display.

3. Important: Do NOT lift, handle, bump, or manipulate the CRT neck/neck board on the Display/Analog
assembly. Modules damaged by mishandling are NOT covered by Apple Warranty. Apple Authorized
Service Providers can be liable for broken CRT necks due to improper handling. Refer to “CRT Neck/
Display/Analog Assembly Handling Information” topic in this chapter for more information.

4. The eMac display/analog assembly requires no voltage calibration or geometry adjustment. Should the
display appear to require adjustment (focus, color, or brightness) use the “Displays” pane under System
Preferences if using Mac OS X. If using Mac OS 9, use the Monitor Control Panel. If you can not make
satisfactory corrections with these tools, replace the display/analog assembly.

5. Important: The microprocessor uses a heatsink/thermal pipe to transfer heat away. Whenever the
heatsink is removed, the bottom side of the heatsink and the top of the microprocessor must be cleaned
and thermal paste must be applied to the microprocessor. If the mating surfaces are not cleaned and
thermal paste is not applied, the CPU may overheat and become damaged. Refer to “Thermal Paste
Application” in this chapter.

6. The hard drive has 3 thermal pads. If the thermal pads become damaged, replace them.

7. The eMac has an optional stand. Refer to the Upgrades chapter or the CIP procedures for instructions
on how to install the stand.

8. The computer has a Power PC G4 microprocessor, running at a clock speed of 700 MHz.

9. The computer comes with 128 MB of SDRAM installed. Two DIMM slots support up to 1 GB using 128
MB, 256 MB, or 512 MB DIMMs. The SDRAM modules are PC-100, 168-pin DIMMs.

10. The computer comes with either tray-loading CD-ROM or DVD-ROM/CD-RW (combo drive).

General Information

eMac Troubleshooting - 1

11. The 56K fax modem is only available on the DVD-ROM/CD-RW (combo drive) model.

12. The eMac uses a different A/C power cord; power cords from older iMac models may not fit into the A/
C socket.

2 - eMac Troubleshooting

General Information

Logic Board, Top

Slots

SDRAM

PMU Reset Button Battery Hard Drive Connector

General Information

VGA Output Port

Ethernet Port

Internal Modem Port

(Not Shown)

FireWire Ports

USB Ports

Sound Input

Port

Sound Output

Port

eMac Troubleshooting - 3

Logic Board, Bottom

Video Processor

Blind Mate Connector

G4 Microprocessor

4 - eMac Troubleshooting

AirPort Slot

Blind Mate Connector

General Information

I/O Ports

General Information

eMac Troubleshooting - 5

The PMU Chip

The PMU (Power Management Unit) is a micro controller chip that controls all power functions
for the computer. The PMU is a computer within a computer. It has memory, software,
firmware, I/O, two crystals, and a CPU. Its function is to:

• Tell the computer to turn on, turn off, sleep, wake, idle, etc.

• Manage system resets from various commands.

• Maintain parameter RAM (PRAM).

• Manage the real-time clock.

Important: The PMU is very sensitive and touching the circuitry on the logic board can cause the

PMU to crash. If the PMU crashes, the battery life goes from about five years to about two days if
the PMU is not reset. Refer to the next topic, “Resetting the PMU on the Logic Board” for the
procedure.

Many system problems can be resolved by resetting the PMU chip. The PMU reset button is
located behind the user access door, refer to the graphic below.

Location of the PMU Reset Button

6 - eMac Troubleshooting

General Information

Resetting the PMU on the Logic Board

Resetting the PMU (Power Management Unit) on the logic board can resolve many system
problems. Whenever you have a unit that fails to power up, you should follow this procedure
before replacing any modules.

1. Save open documents and quit all open applications.

2. Turn the computer off by choosing Shut Down from the Special menu (if using Mac OS 9), or choose
Shut Down from the Apple menu if using OS X.

3. Remove the user access door.

General Information

eMac Troubleshooting - 7

4 Unplug all cables, except the power cord, from the computer.

5 Touch a metal surface inside the computer. Then unplug the power cord.This helps protect the

computer from damage caused by electrostatic discharge. Important: To avoid electrostatic
discharge, always ground yourself by touching metal before you touch any parts or install components
inside the computer. To avoid generating static electricity, do not walk around the room until you have
finished the procedure and closed the computer.

8 - eMac Troubleshooting

General Information

6 Press the PMU reset button (shown below) once and then proceed to step 7. Do NOT press the

PMU reset button a second time because it could crash the PMU chip.

7 WAIT ten seconds before connecting the power cord and powering the computer on. If the

computer powers on, go to the next step. If the computer does not power on, there is something
else wrong with the computer, refer to the symptom/cure, “No Power” in this chapter.

8 Run MacTest Pro and return the computer to the customer.

Note: This entire procedure resets the computer’s PRAM. Be sure to reset the computer’s time,

date and other system parameter settings before returning the computer to the customer.

General Information

eMac Troubleshooting - 9

Power-On Self Test

There is a power-on self test that resides in the ROM of the eMac. This test automatically runs
whenever the eMac is powered on after being fully shut down (the power-on self test does not
run if the machine is only restarted).

If a problem is detected during the test, you will not hear a normal startup chime. Instead, the
system will beep as explained below. Refer to “Error Beeps” later in this chapter for
instructions on how to troubleshoot and repair an eMac that sounds error beeps at startup time.

Following is a definition of what the error beeps at startup time signify.

One Beep: No RAM is installed or detected.

Two Beeps: Incompatible memory is installed. (The slots accept standard PC-100 or PC-

133, 168-pin DIMMs).

Three Beeps: No RAM banks passed memory testing.

Four or Five Beeps: Bad checksum for the remainder of the boot ROM. The ROM is bad.

10 - eMac Troubleshooting

General Information

Logic Board Battery

Important: Apple highly recommends removing the battery when handling the logic board. Make

sure to use proper ESD protection when handling modules.

The battery on the logic board controls the stored system settings, such as date and time. It is only
necessary to test the battery when you can’t power on the computer, or the date and time are reset
every time the AC power is removed.

The battery is also used to power the PMU chip (because the PMU chip keeps time and must always
be running) when the computer is unplugged from the wall (AC power). The PMU is
and touching any circuitry that is connected to the PMU can cause it to crash. If the PMU crashes,
the battery life goes from about five years to about two days if the PMU is not reset. Once the
battery goes dead, the PMU will reset the time and date every time the AC power is removed. To fix
this situation, replace the battery and reset the PMU (refer to “Resetting the PMU on the Logic
Board” mentioned earlier in this chapter).

very sensitive

Testing the Battery

If the computer has a “No Power” situation, check the battery before replacing modules. A drained
battery may be indicative of a crashed Power Management Unit.

With the battery in the battery holder (under load), measure the voltage across the battery’s
positive and ground terminals.

Does the battery measure at least +3.5v? If not, replace the battery and reset the PMU. If the
battery does measure over +3.5v, reinstall the battery and reset the PMU as above

Connect the power cord and power up the system again.

General Information

eMac Troubleshooting - 11