Apple | iMac (Summer 2000) | Repair manual | Apple iMac (Summer 2000) Repair manual

Apple iMac (Summer 2000) Repair manual
K Service Source
iMac (Summer 2001)
Updated 11July 2005
© 2001 Apple Computer, Inc. All rights reserved.
K Service Source
Take Apart
iMac (Summer 2001)
Updated 11 July 2005.
Take Apart
- 2
What’s New
New Models
There are four models of the
iMac: the 500 MHz iMac in
Indigo (Education only), the
500 MHz in Indigo and
Snow, the 600 MHz iMac in
Graphite and Snow, and the
700 MHz iMac Special
Edition in Graphite and
Snow.
Note: The 500 MHz
Education iMac uses logic
board 661-2447.
Take Apart
- 3
Part Changes for iMac (Summer 2001)
• Logic boards:
– added 661-2548, 700 MHz board
– 661-2447, 500 MHz board is now used in
educational iMacs, previously it was an
international board only
• Hard drives:
– added 661-2521, 60 GB Hard Drive
• External plastics
– added 922-4609, Front Outer Bezel, Snow, Rev. 2
Take Apart
- 4
The following take apart
procedures for the iMac
(Summer 2001) computers
are identical to take apart
procedures for iMac (Early
2001) and iMac (Summer
2000) computers.
The Indigo Mac (Summer
2000) was used for all the
pictures in this chapter.
Take Apart
- 5
Tools
The following tools are
recommended for the take
apart procedures:
• phillips screwdriver
(No.1 and No.2)
• a stubby (short) phillips
screwdriver
• plastic flatblade
screwdriver to release
tabs on plastic housing
• jeweler’s screwdriver
• CRT discharge tool
• needlenose pliers
• ESD mat
Take Apart
Bottom Housing With Flip Foot - 6
Procedures
Bottom Housing With
Flip Foot
Before you begin, position
the computer face down,
resting the computer on an
ESD mat or other soft
surface.
Take Apart
Bottom Housing With Flip Foot - 7
1. Using a plastic flatblade
screwdriver, remove
the VGA vented cover.
2. Remove the two screws
near the flip foot.
Take Apart
Bottom Housing With Flip Foot - 8
3. Remove the video out
access door from the
bottom housing.
Take Apart
Bottom Housing With Flip Foot - 9
4. Remove the two outer
screws located near the
video out port.
Replacement Note: The
bottom housing uses two
sizes of screws. The two
shorter screws attach
near the flip foot.
Take Apart
Bottom Housing With Flip Foot - 1 0
5. Pull the bottom housing
off the computer.
Take Apart
Bottom Housing With Flip Foot - 1 1
Bottom Housing
Replacement Note
1. Align the three tabs on
the bottom housing with
the tab slots on the front
outer bezel.
Ensure that the center
tab is properly aligned
or CDs and DVD discs
may not eject from the
slot.
2. Lower the bottom
housing into place and
replace the screws.
Take Apart
EMI Cover - 1 2
EMI Cover
Before you begin:
• Position the computer
upside down, resting the
computer on an ESD mat
or other soft surface.
• Remove the bottom
housing.
Take Apart
EMI Cover - 1 3
1. Remove the six screws
on the EMI cover.
Take Apart
EMI Cover - 1 4
2. Lift the EMI cover off the
computer.
Note: Be careful of the
VGA output port.
Take Apart
EMI Cover - 1 5
Replacement Note: Position
the rear of the EMI cover
into place first, positioning
the EMI cover over the video
port (if present). Continue
lowering the cover into
place by gently squeezing in
on both sides, as you lower
the cover into position.
Take Apart
SDRAM DIMM - 1 6
SDRAM DIMM
Before you begin, position
the computer face down,
resting the CRT on an ESD
mat or other soft surface.
Take Apart
SDRAM DIMM - 1 7
1. With a flatblade
screwdriver or coin,
turn the colored latch
counterclockwise on the
access door.
2. Pull the access door
down to open.
Take Apart
SDRAM DIMM - 1 8
3. Push down on the plastic
tabs to release the
SDRAM module(s).
4. Carefully lift the SDRAM
from the slot.
Note: Remove installed
SDRAM from the logic board
before returning the logic
board to Apple.
Take Apart
AirPort Card - 1 9
AirPort Card
Before you begin, position
the computer face down,
resting the CRT on an ESD
mat or other soft surface.
Note: If the AirPort Card is
not installed, a protective
antenna cap will be attached
to the antenna.
Take Apart
AirPort Card - 2 0
1. With a flatblade
screwdriver or coin,
turn the colored latch to
open the access door.
The antenna and AirPort
Card will be visible
when you open the access
door.
Note: If the AirPort card
is not installed, a clear
protective antenna cap
will be attached to the
antenna.
Take Apart
AirPort Card - 2 1
2. Remove the AirPort Card
by lifting the card
straight up and out of the
card guides and
connector.
Take Apart
AirPort Card - 2 2
3. Disconnect the antenna
from the small hole
AirPort Card.
Take Apart
AirPort Card - 2 3
4. Remove the ground clip
from the AirPort
Adapter Card.
5. Using the pull tab,
separate the AirPort
Card from the adapter
card.
Take Apart
CD/HD Carrier - 2 4
CD/HD Carrier
Before you begin, position
the computer upside down,
resting the computer on an
ESD mat or other soft
surface and remove the
following:
• bottom housing
• EMI cover
• SDRAM
Take Apart
CD/HD Carrier - 2 5
1. Remove the four screws
connecting the CD/HD
drive carrier to the
metal chassis (also
known as the divider
panel).
Take Apart
CD/HD Carrier - 2 6
2. Disconnect the following
cables fro the back of the
CD/HD carrier:
• hard drive power
cable
• hard drive data cable
• CD-ROM/DVD-ROM
data cable
• logic board cable
connector
Take Apart
CD/HD Carrier - 2 7
3. Tilt the CD/HD carrier
forward and lift the
carrier out of the
computer.
Note: Continue with the
Take Apart procedures if you
are replacing the CD-ROM,
DVD-ROM, or the hard
drive.
Take Apart
CD-ROM / DVD-ROM/CD-RW - 2 8
CD-ROM / DVDROM/CD-RW
Note: The procedures for
removing a CD-ROM, DVDROM and CD-RW are
identical. This procedure
will reference the CD-ROM
Take Apart.
Before you begin, position
the computer upside down,
and remove the following:
• bottom housing
• EMI cover
• SDRAM
• CD/HD carrier
Take Apart
CD-ROM / DVD-ROM/CD-RW - 2 9
1. Using a Phillips
screwdriver, remove
the CD/HD carrier
mounting screws (two on
each side).
Take Apart
CD-ROM / DVD-ROM/CD-RW - 3 0
2. Carefully turn the
CD/HD drive carrier
over.
3. Holding onto the CD-ROM
from the rear, lift the
CD-ROM carrier out of
the CD/HD carrier.
Important: Don’t press
or squeeze the front of
the CD-ROM. Squeezing
the front could bend the
metal housing, making it
impossible to insert or
remove a CD or DVD disc.
Take Apart
CD-ROM / DVD-ROM/CD-RW - 3 1
4. Using a jeweler’s
screwdriver, remove
the four screws (two on
each side) on the CD/
DVD carrier.
5. Lift the CD-ROM from
its carrier.
Take Apart
CD-ROM / DVD-ROM/CD-RW - 3 2
6. On the back of the CDROM, Use a jeweler’s
screwdriver to remove
the two screws on the
adapter board.
7. Remove the adapter
board from the CD-ROM.
Note: Return the drive
to Apple without the
cables, carrier, or the
adapter board. Refer to
the parts database for
more information.
Take Apart
CD-ROM / DVD-ROM/CD-RW - 3 3
CD-ROM, DVD-ROM,CDRW Module Replacement
Position the drive into its
carrier as shown.
1. Check that the yellow
warning label is face up.
Note: if you are
installing a new drive
carrier, remove the blue
film covering the
grounding pad.
Take Apart
CD-ROM / DVD-ROM/CD-RW - 3 4
2. Lower the CD/DVD
carrier into the CD/HD
carrier.
3. Push the CD/DVD
carrier forward so the
carrier tabs go through
the holes on the CD/HD
carrier.
4. Replace the CD/HD
carrier screws.
Take Apart
CD-ROM / DVD-ROM/CD-RW - 3 5
5. Holding the drive
carrier in the
orientation shown, make
sure the CD-ROM or
DVD-ROM is correctly
installed into the CD/HD
carrier.
6. Make sure the Slave/
Master switch on the
back of the drive is still
set to the Slave mode
(set to the left).
Take Apart
CD/DVD/CD-RW Adapter Board - 3 6
CD/DVD/CD-RW
Adapter Board
Before you begin, position
the computer upside down,
resting the computer on an
ESD mat or other soft
surface and remove the
following:
• bottom housing
• EMI cover
• SDRAM
• CD/HD carrier
Take Apart
CD/DVD/CD-RW Adapter Board - 3 7
1. Using a jeweler’s
screwdriver, remove
the two screws on the
CD/DVD adapter board.
2. Remove the adapter
board from the back of
the CD-ROM.
Note: Return the CD/DVDROM drive to Apple without
the cables, carrier, or the
adapter board. Refer to the
parts database for more
information.
Take Apart
Hard Drive - 3 8
Hard Drive
Before you begin, position
the computer upside down,
resting the computer on an
ESD mat or other soft
surface and remove the
following:
• bottom housing
• EMI cover
• SDRAM
Take Apart
Hard Drive - 3 9
1. Disconnect the following
cables on the back of the
hard drive:
• Hard drive power
cable
• Hard drive data cable
Take Apart
Hard Drive - 4 0
Note: The hard drive
carrier shown was
removed from the
computer. However, you
can easily remove the
hard drive while the
carrier is still screwed
down to the chassis.
Continue with the
procedure.
2. Using a #1 Phillips
screwdriver, remove
the four hard drive
mounting screws.
Take Apart
Hard Drive - 4 1
3. Slide the hard drive out
of the CD/HD carrier.
Note: Return the drives
without the cables or
carriers. Exchange Apple
hard drive modules likefor-like in Apple packaging.
Failure to comply with this
requirement may result in a
packaging noncompliance
charge. Refer to the parts
database for more
information.
Take Apart
Hard Drive - 4 2
Hard Drive Replacement
When installing the hard
drive into the CD/HD
carrier, make sure the hard
drive is component side up
(as shown).
Take Apart
Logic Board - 4 3
Logic Board
Before you begin, position
the computer upside down,
resting the computer on an
ESD mat or other soft
surface and remove the
following:
• bottom housing
• EMI cover
The logic board and the down
converter board are
removed together (still
connected to each other), and
are separated once they are
removed from the computer.
Take Apart
Logic Board - 4 4
Note: Remove SDRAM to
make cable removal easier.
1. On the back of the CD/HD
carrier, disconnect the:
• hard drive power
cable
• hard drive data cable
• CD-ROM/DVD-ROM
data cable
• logic board cable
connector
2. Disconnect the antenna if
it’s connected to the
AirPort Card, or it it’s
attached to the protective
antenna cap.
Take Apart
Logic Board - 4 5
3. Remove the six screws
on the logic board and
five screws on the down
converter board.
Note: The two screws
located at the top of the
down converter board
(near the speaker) are
larger screws than the
other screws (with
washers).
Take Apart
Logic Board - 4 6
4. Gently lift the down
converter board and
logic board out of the
computer.
Take Apart
Logic Board - 4 7
5. Using a flatblade
screwdriver, pry the
plastic rivet off the
board.
Put the top half of the
rivet back into the
bottom half so it doesn’t
get lost.
Take Apart
Logic Board - 4 8
6. Holding onto the down
converter, press down
on the black connector to
separate the down
converter board from
the logic board.
Note: If you are returning
the logic board to Apple
refer to the parts database
and remove the SDRAM, any
cables, the modem, the
AirPort Card, and I/O panel.
Replacement Note: When
reinstalling the logic board,
refer to the next page about
installing a thermal pad.
Take Apart
Logic Board - 4 9
Thermal Pad Information
The following logic boards
use a thermal pad:
• 661-2425, 500 MHz
• 661-2426, 600 MHz
• 661-2458, 700 MHz
Back View
Thermal Pad
Front
View
The thermal pad prevents
the microprocessor from
overheating. It is crucial
that a new thermal pad be
used each time you detach
the logic board from the
divider panel assembly.
(Exception: if you are
testing the logic board and
detach it for a few minutes).
Take Apart
Logic Board - 5 0
Thermal Pad Installation
1. Remove the old thermal
pad from the
microprocessor (or, it
may be stuck to the
divider panel).
Thermal
Pad
2. Remove the protective
backing from either side
of the new thermal pad
and place it on the
microprocessor.
3. Press down on the pad to
make sure it has even
contact without air
pockets.
4. Remove the protective
Take Apart
Logic Board - 5 1
backing from the exposed
side of the thermal pad.
5. Install the logic board
back on to the divider
panel.
Note: Avoid unnecessary
contact with either side of
the thermal pad as dirt or
body oils reduce the thermal
conductivity of the pad.
Thermal
Pad
Divider Panel
For additional information,
refer to Kbase article
58792, “Microprocessor
Thermal Pad Replacement”.
Take Apart
Down Converter Board - 5 2
Down Converter Board
Before you begin, position
the computer upside down,
resting the computer on an
ESD mat or other soft
surface and remove the
following:
• bottom housing
• EMI cover
Note: The logic board and
the down converter board
are removed together (still
connected to each other), and
are separated once they are
removed from the computer.
Take Apart
Down Converter Board - 5 3
Note: Remove SDRAM to
make cable removal easier.
1. On the back of the CD/HD
carrier, disconnect the:
• hard drive power
cable
• hard drive data cable
• CD-ROM/DVD-ROM
data cable
• logic board cable
connector
2. Disconnect the antenna if
it’s connected to the
AirPort Card, or it it’s
attached to the protective
antenna cap.
Take Apart
Down Converter Board - 5 4
3. Remove the six screws
on the logic board and
five screws on the down
converter board.
Note: The two down
converter screws located
near the speaker are
larger screws than the
rest of the down
converter screws.
Take Apart
Down Converter Board - 5 5
4. Lift the boards out of the
computer.
Take Apart
Down Converter Board - 5 6
5. Using a flatblade
screwdriver, pry the
rivet off the logic board.
Put the top half of the
rivet back into the
bottom half so it doesn’t
get lost.
Take Apart
Down Converter Board - 5 7
6. Holding onto the boards,
press down on the black
connector and separate
the down converter
board from the logic
board.
Replacement Note: When
reinstalling the logic
board, make sure the
antenna wire is not
underneath the board.
Take Apart
Modem - 5 8
Modem
Before you begin, position
the computer upside down,
resting the computer on an
ESD mat or other soft
surface and remove the
following:
• bottom housing
• EMI cover
• logic board
Note: The modem is located
on the underside of the logic
board.
Take Apart
Modem - 5 9
1. With the logic board
facing right side up,
disconnect the cable at
J12.
2. Remove the two screws
on the I/O panel.
Take Apart
Modem - 6 0
3. Turn the logic board to
the underside and
remove the modem
screw.
Take Apart
Modem - 6 1
4. Rotate the logic board
right side up again.
Carefully slide the I/O
panel off the logic board.
Note: As you slide the
I/O panel off the logic
board, support the
modem with your other
hand so the modem
doesn’t fall off the logic
board.
5. Remove the modem from
its connector slot on the
underside of the logic
board.
Take Apart
Modem - 6 2
Modem Replacement
The I/O panel and the modem
are sandwiched between the
logic board and the metal
frame of the I/O panel. The
metal frame fits on top of the
logic board, over the screw
holes. On the underside of
the logic board, the screw
tab goes under the modem.
Replacement Note: After
replacing an international
modem, use the Modem
Country Selector utility to
set the modem to the correct
country.
Take Apart
I/O Panel - 6 3
I/O Panel
Before you begin, position
the computer upside down,
resting the computer on an
ESD mat or other soft
surface and remove the
following:
• bottom housing
• EMI cover
• logic board
Take Apart
I/O Panel - 6 4
1. Disconnect the cable at
J12, going from the
logic board to the I/O
panel.
2. Remove the two screws
on the I/O panel.
Take Apart
I/O Panel - 6 5
3. Turn the logic board
over and remove the
modem screw.
Take Apart
I/O Panel - 6 6
4. Rotate the logic board
face up again and
carefully slide the I/O
panel off the logic board.
Note: As you slide the
I/O panel off the logic
board, support the
modem with your hand so
the modem doesn’t fall
off the logic board.
Take Apart
Front Outer Bezel - 6 7
Front Outer Bezel
Before you begin, place the
computer on an ESD mat and
remove the bottom housing.
Note: The Snow iMac has a
new part number for the
front outer bezel, 9224609.
Take Apart
Front Outer Bezel - 6 8
1. With a jeweler’s
screwdriver, carefully
remove the two tabs on
the front outer bezel.
Refer to the next graphic
for a close-up of the tab
removal.
Take Apart
Front Outer Bezel - 6 9
2. After removing the tabs,
remove the screws
located under the tabs.
Take Apart
Front Outer Bezel - 7 0
Note: The bezel tabs fit
tightly into the rear
housing. A good, hard pull
upward is required to
release all the tabs.
3. Insert a plastic tool
underneath the bezel.
4. Pry the outer bezel tabs
from the rear housing
with a plastic tool. As
you push and pry the tool
inside the bezel, the side
tabs will start to
release.
5. Insert the tool on the left
side of the bezel and
repeat.
Take Apart
Front Outer Bezel - 7 1
6. As the tabs start to
release, pull hard on the
front outer bezel to
release the tabs
completely.
Take Apart
Top Rear Housing - 7 2
Top Rear Housing
±
Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety. From the
Service Source Online home
page, click Troubleshoot and
Repair. Then click on Safety
under the Tools list.
Before you begin, rest the
computer on an ESD mat and
remove the following:
• bottom housing
• front outer bezel
Take Apart
Top Rear Housing - 7 3
1. Remove the two tabs
(screw caps) on the top
inner bezel. Refer to the
next page for a close-up
of the tab removal.
Take Apart
Top Rear Housing - 7 4
2. Pry the tabs off, and
remove the two screws
under each tab.
Take Apart
Top Rear Housing - 7 5
3. Position the computer
face down.
4. Remove four screws and
loosen the fixed screw
(at the top) on the rear
housing.
Take Apart
Top Rear Housing - 7 6
5. Position the computer
right side up. Push down
and pull out on the rear
housing to unhook the
rear housing tabs that
connect to the inner
bezel.
Take Apart
Top Rear Housing - 7 7
6. Lift the top rear housing
off the computer.
Take Apart
Divider Panel - 7 8
Divider Panel
Many service parts, such as
the speakers, power/
analog/video board, side
panels, cables, and the
headphone board, are
connected to the divider
panel. The divider panel is
the metal chassis with EMI
foam.
The divider panel is not
available as a service part
on the iMac (Early 2001)
computer.
Take Apart
Divider Panel - 7 9
The thermal pad (A) and the
divider panel(B) are used on
the following logic boards:
• 661-2425, 500 MHz
• 661-2426, 600 MHz
• 661-2458, 700 MHz
Take Apart
Power/Analog/Video Board - 8 0
Power/Analog/Video
Board
Before you begin, discharge
the CRT, rest the computer
on an ESD mat or other soft
surface and remove the
following:
• bottom housing
• front outer bezel
• top rear housing
Note: There are two power/
analog/video boards, part
number 661-2465 (with a
switch at SW901) and 6612466. Exchange like-forlike.
Take Apart
Power/Analog/Video Board - 8 1
±Warning:
This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
discharge the CRT.
1. Disconnect the
microphone connector
located near the top of
the CRT.
2. Unwrap the bendable
cable wraps in the upper
left and upper right
corners of the CRT.
3. Disconnect the anode cap.
Take Apart
Power/Analog/Video Board - 8 2
4. Lift the degauss cable out
of the way to access the
side panel screws.
5. Using a narrow shaft
screwdriver, remove
the four side panel
screws (two on each
side) that attach the left
and right side panels to
the inner bezel.
Take Apart
Power/Analog/Video Board - 8 3
6. Open the CRT cable
clamps. Remove the
wires from the cable
clamps.
Take Apart
Power/Analog/Video Board - 8 4
7. Partially lift the side
panels (with the power/
analog/video board
attached to the divider
panel) up and off the
inner bezel to gain
access to connector
P501 located at the
bottom of the power/
analog/video board.
Take Apart
Power/Analog/Video Board - 8 5
8. Disconnect P501 and
P701 on the power/
analog/video board. The
cables are located near
the high voltage
capacitor.
Take Apart
Power/Analog/Video Board - 8 6
9. On the other side of the
CRT neck, disconnect the
brown degauss cable,
P901, from the power/
analog/video board.
Remove P901 from the
cable clamp.
Take Apart
Power/Analog/Video Board - 8 7
10. At the very bottom of the
power/analog/video
board, near the bottom of
the CRT, disconnect
P902, which is part of
the audio/headphone/
LED/speaker cable
assembly.
Take Apart
Power/Analog/Video Board - 8 8
11. Disconnect the two
ground cables on the
video board.
Important: Be careful when
working around the CRT
neck rings. If the neck rings
are bumped, the CRT will be
knocked out of adjustment,
and will require
replacement of the CRT.
Take Apart
Power/Analog/Video Board - 8 9
12. Loosen the CRT neck
clamp screw.
Take Apart
Power/Analog/Video Board - 9 0
13. Carefully pull the video
board off the CRT neck.
Take Apart
Power/Analog/Video Board - 9 1
14. Holding on to the side
panels, lift the power/
analog/video board
(which is attached to the
side panels and divider
panel) from the inner
bezel.
Take Apart
Power/Analog/Video Board - 9 2
15. Remove the ten screws
and pinch the two
standoffs with a
needlenose pliers to lift
the power/analog board
off the divider panel.
Take Apart
Power/Analog/Video Board - 9 3
16. Lift the board from the
flyback transformer
side to clear the power
plug from the side panel.
17. Pull the board forward
toward the speakers.
Replacement Note: If you’re
returning the power/
analog/video board to Apple,
exchange the board likefor-like and leave the cables
attached to the board.
Take Apart
Power/Analog/Video Board - 9 4
ßπ 6 6 1 - 2 4 6 5
(with switch at SW901)
Identifying Power/Analog/
Video Boards
There are two power/
analog/video boards in
service stock. The part
numbers are 661-2465 and
661-2466. These boards
must be exchanged like-forlike.
661-2466
The 661-2465 board can be
identified by the presence of
a switch at location SW901,
located near the flyback
transformer. Refer to the
next page for switch
instructions.
Take Apart
Power/Analog/Video Board - 9 5
Switch Instructions
If the iMac has the analog
board with the switch, the
switch must be set for the
type of the CRT (LG or CPT)
tube in the computer.
If the power/analog/video
board or the CRT are
replaced, make sure to set
the switch to the
appropriate position.
Refer to the next page for
information on how to
identify an LG and CPT CRT.
Take Apart
Power/Analog/Video Board - 9 6
LG CRT
Identify an LG CRT by the
black plastic molding located
on the CRT neck. The LG
molding has the LG name at
the top and three holes.
If the iMac uses the 6612465 power/analog board
(with the switch) and the
tube is an LG CRT, make sure
the switch is set to LG.
Take Apart
Power/Analog/Video Board - 9 7
CPT CRT
Identify a CPT CRT by the
black plastic molding located
on the CRT neck. The CPT
molding has two holes in the
molding.
If the iMac uses the 6612465 power/analog board
(with the switch) and the
tube is a CPT CRT, make
sure the switch is set to CPT.
Take Apart
Side Panels - 9 8
Side Panels
±
Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
discharge the CRT.
Before you begin, discharge
the CRT, rest the computer
on an ESD mat or other soft
surface and remove the
following:
• bottom housing
• front outer bezel
• top rear housing
Take Apart
Side Panels - 9 9
1. Undo the wire wraps in
the top corners or the
CRT.
2. Lift the degauss cable out
of the way to access the
side panel screws. There
are two screws on each
side.
Take Apart
Side Panels - 1 0 0
3. On the rear of the side
panels, remove four
screws. These screws
connect the side panels to
the divider panel (the
metal chassis).
Take Apart
Side Panels - 1 0 1
4. At the top rear of the side
panels, pull each side
panel off the plastic pin.
(The left and right side
panels are identified
when viewing the
computer from the
rear.)
Note: To separate the left
panel from the right panel,
remove the two rear bracket
screws. Otherwise, lift the
side panels off as a unit
(next graphic) and separate
the panels later.
Take Apart
Side Panels - 1 0 2
5. Pull the panels out to the
sides a bit, and then lift
the side panels up and off
the computer.
Take Apart
Side Panels - 1 0 3
6. Carefully remove the
antenna wire from each
side panel.
7. Pull the side panel off
the metal divider panel.
If necessary, repeat
these steps for the other
side panel.
Take Apart
Antenna - 1 0 4
Antenna
±
Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
discharge the CRT.
Before you begin, rest the
computer on an ESD mat or
other soft surface and
remove the following:
• antenna from the AirPort
Card (if installed) or
from the clear antenna
holder located near the
SDRAM DIMMs
• bottom housing
Take Apart
Antenna - 1 0 5
• front outer bezel
• top rear housing
• divider panel assembly
Take Apart
Antenna - 1 0 6
1. Remove the three screws
and cable clip on the
antenna.
Take Apart
Antenna - 1 0 7
2. Important: Note how the
antenna wire is routed
through the side panel
before removing. A
close-up view of the
right panel antenna is
shown here.
Carefully remove the
antenna from the right
side panel.
Take Apart
Antenna - 1 0 8
3. Carefully remove the
antenna from the left
side panel. Refer to the
next page for a close up
of the antenna in the left
side panel.
Take Apart
Antenna - 1 0 9
4. This shows a close up
view of the antenna in
the left side panel.
Take Apart
Antenna - 1 1 0
5. Before removing the
antenna from the divider
panel, mark the hole
(with a pen tip) that the
antenna passes through
so you know which hole
the antenna goes into
when replacing the
antenna.
Take Apart
Antenna - 1 1 1
6. Remove the antenna
board from the divider
panel.
Take Apart
Speakers - 1 1 2
Speakers
Before you begin, rest the
computer on an ESD mat or
other soft surface, and
remove the bottom housing.
The EMI cover is removed in
this photo, but it is not
necessary to remove it to
access the speakers.
Take Apart
Speakers - 1 1 3
1. Disconnect the short
speaker cable next to the
speaker.
2. Note: If you are certain
a speaker is faulty, the
easiest removal method
is to gently push the
speaker down in the
direction of the arrow.
This will bend the
biggest tab (there are
three tabs) that connects
the speaker to the
divider panel.
3. Twist the speaker back
and forth and slide it off
the divider panel.
Take Apart
Headphone Board - 1 1 4
Headphone Board
±
Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
discharge the CRT.
Before you begin, remove
the:
• bottom housing
• front outer bezel
• top rear housing
• divider panel assembly
(with side panels, power/
analog board, and
speakers attached)
Take Apart
Headphone Board - 1 1 5
1. Turn the divider panel
over.
2. Remove the speaker to
access the headphone/
audio board screw.
3. remove the screw using
a stubby (short)
screwdriver.
4. Disconnect the connector
from the headphone
board.
5. Remove the headphone
board from the divider
panel.
Take Apart
Power/LED Board - 1 1 6
Power/LED Board
±
Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
discharge the CRT.
Rest the computer on an ESD
mat or other soft surface,
and remove the following:
• bottom housing
• front outer bezel
• top rear housing
• divider panel assembly
Take Apart
Power/LED Board - 1 1 7
1. Turn the divider panel
over and remove the
speaker to access the
power/LED board screw.
2. Remove the screw using
a stubby screwdriver.
3. Disconnect the cable
from the connector.
4. Remove the power/LED
board from the divider
panel.
Take Apart
CRT - 1 1 8
CRT
±
Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety on
Service Source online and
discharge the CRT.
Rest the computer on an ESD
mat or other soft surface,
and remove the following:
• bottom housing
• front outer bezel
• top rear housing
• divider panel assembly
Take Apart
CRT - 1 1 9
1. Remove the four CRT
screws.
2. Remove the ground wire.
3. Lift the CRT from the
inner bezel.
Caution: Be careful when
working around the CRT
neck rings. If the neck rings
are bumped, the CRT will be
knocked out of adjustment,
and will require
replacement of the CRT.
Take Apart
Replacing the CRT - 1 2 0
Replacing the CRT
CRT Notice, July 2005
Two vendors (LG and CPT)
used to supply the CRT for
all iMac computers with a
slot-loading CD-ROM, DVDROM, or CD-RW drive.
As of July 2005, Apple
Service will carry only the
CPT CRT (shown).
Important: The CPT CRT
must be paired with a Hon
Hai power/analog board,
either 661-2465 or 6612315.
Take Apart
Replacing the CRT - 1 2 1
1. When you replace the
CRT, identify if the
computer has an LG or
Hon Hai power/analog
board installed.
• Hon Hai boards have a
switch at SW901 (see
graphic).
• LG boards do not have a
switch at SW901 and
are not compatible
with the CPT CRT.
Take Apart
Replacing the CRT - 1 2 2
2. If you have an LG board,
(shown on the left) you
need to order a Hon Hai
board: 661-2465 or
661-2315.
3. Set the switch on the Hon
Hai board, SW901 to
CPT.
Take Apart
Replacing the CRT - 1 2 3
Switch Settings for the LG
CRT
If you have an LG CRT, and a
Hon Hai power/analog board,
set the switch on the Hon Hai
board to LG.
One way to quickly identify
an LG CRT is by the black
sticker located on the left
side of the CRT. The sticker
covers the LG vendor label.
Refer to Kbase article
95060 for more
information on how to
identify CRT models.
Take Apart
Replacing the CRT - 1 2 4
Identifying the LG CRT
Identify the LG CRT by the
plastic molding on the CRT
neck. The LG name and three
holes can be seen on the
plastic molding.
If the iMac uses the 6612465 power/analog board
(with the switch) and the
tube is an LG CRT, make sure
the switch is set to LG.
Take Apart
Replacing the CRT - 1 2 5
Identifying the CPT CRT
The CPT CRT can be
identified by the plastic
molding on the CRT neck. The
CPT CRT molding has two
holes in the molding.
If the iMac uses the 6612465 power/analog board
(with the switch) and the
tube is a CPT CRT, make
sure the switch is set to CPT.
Take Apart
Microphone - 1 2 6
Microphone
±
Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety on
Service Source online.
Before you begin, discharge
the CRT, rest the computer
on an ESD mat or other soft
surface, and remove the
following:
• bottom housing
• front outer bezel
• top rear housing
Take Apart
Microphone - 1 2 7
1. Unwrap the bendable
cable wrap.
2. Disconnect the
microphone connector.
Take Apart
Microphone - 1 2 8
3. Pull the microphone
from the inner bezel.
Take Apart
Microphone - 1 2 9
Replacing the Microphone
1. Insert the microphone
into the inner bezel with
the loop facing down,
toward the CRT.
2. Push the microphone
through the hole on the
inner bezel (see photo on
the next page).
Take Apart
Microphone - 1 3 0
3. Check that the
microphone protrudes
through the inner bezel
hole.
Troubleshooting
Introduction - 1
Introduction
Troubleshooting procedures for the iMac (Summer 2001) computers are almost identical to the iMac (Early 2001) and iMac
(Summer 2000) computers. Read below to see what’s new and
different.
Troubleshooting information for the iMac can also be found in
Apple’s Knowledge Base (http://kbase.info.apple.com). Refer to
article 95143, iMac: Troubleshooting Procedures, or to article
95148, iMac (Summer 2001): Service Repair Manual.
What’s New and Different:
1.
Important: The following logic boards use a thermal pad
(922-4364) to help cool the microprocessor: 661-2425,
500 MHz, 661-2426, 600 MHz, and 661-2458, 700 MHz.
If this pad is not replaced when the main logic board is separated from the divider panel assembly, the microprocessor
may overheat and become damaged.
It is crucial that a fresh thermal pad be used each time you
detach the logic board from the divider panel. (An exception
would be if you are simply testing the logic board and only
detach it for a few minutes).
2.
The 500 MHz iMac (Summer 2001) for education uses logic
board 661-2447. All other 500 MHz iMac (Summer 2001)
computers use the 661-2425 logic board.
Troubleshooting
Introduction - 2
Searching the Knowledge Base
In the Knowledge Base, use the expert search to locate troubleshooting articles. In the expert search window, type in the keywords: “kssts” and “imac”, click the “Use ALL words (AND)”
radio button and then click the Continue button (see Figure 1
below).
Here are some other keywords you can use to locate iMac articles:
•
kimac (for original imac or generic iMac articles)
•
kimacsl (for iMac slot loading)
•
kimacs2k (for iMac Summer 2000)
•
kssadj (for Service Source adjustment articles)
•
kssev (for Service Source exploded view articles)
•
kssta (for Service Source take apart articles)
F i g u r e 1 Knowledge Base Expert Search Window
Troubleshooting
Troubleshooting Procedures - 3
Troubleshooting Procedures
This chapter contains basic theory of operations information as
well as detailed Symptom/Cure tables, both of which should help
you troubleshoot and repair the iMac (Summer 2001) computer.
The Symptom/Cure tables are broken down into two sections:
problems that can occur at startup time-before the Finder
appears on the screen; and problems that can occur after a
successful startup. Each major symptom has its own symptom/
cure table.
In the left-hand column of each table are the possible causes of the
symptom, with the corresponding cures in the right-hand column.
You should also follow the tables in the order presented as they
represent the most logical order for cause and cure. Verify
whether or not the product continues to exhibit the symptom. If
the symptom persists, try the next cure. ( Note: If you have
replaced a module, reinstall the original module before you
proceed to the next fix.)
For additional assistance, contact Apple Technical Support.
Troubleshooting
Block Diagram/ Searching the Knowledge Base - 4
Block Diagram
System Block Diagram
The following illustration providesElectronics
an overview of the iMac
Digital
internal components and shows
Video
Neck
Board
Hard
Drive
CD-ROM
Drive
how they are connected.
Analog Electronics
Main
Logic
Board
Yoke
Power Supply and
Video Deflection Board
Modem
AirPort/
Adapter
Card
EMI Cover
Power Supply
Down Converter
CRT
Speakers,
Headphone Jacks,
Microphone,
Power/Led Board
Troubleshooting
Power Flow - 5
Power Flow
Power is controlled in the iMac system by the power/analog
board. Once the unit is plugged in, power flows from the AC outlet
at the wall to the AC inlet on the power/analog board. From there,
the power flows through the main cable on the power/analog
board, to the video neck board, down converter board, logic board,
and all its attached components.
Troubleshooting
Testing for Power - 6
Testing for Power
The iMac requires trickle voltage (+5 TRKL) in order to poweron. If you are experiencing power problems in the iMac unit, you
will want to test for trickle power to pinpoint the location of the
problem and to determine whether or not the power supply/analog
board is functioning normally. If you have trickle power in the
system, the odds are your power/analog board is OK.
In general, you should test for power at the AC outlet first. Next, it
is best to check the logic board. In this way, you will be able to
immediately pinpoint which module is failing.
The following procedures will explain how to test for power at the
AC outlet and at the logic board.
At the AC Outlet
If the unit will not power up from the keyboard, first, unplug the
keyboard from the computer. Then, using a known-good power
cord, power-on the system using the power button on the front of
the computer. If the system powers on, you can assume the AC outlet is good and the problem is with the keyboard. If the system still
won’t power on, try connecting to a different AC outlet. If the unit
powers on this time, you most likely have a problem with the AC
outlet. If you still have no power, you may need to reset the PMU
chip (power manager) on the logic board (refer to “Resetting the
Logic Board” in this chapter).
Troubleshooting
Testing for Power - 7
At the Logic Board
With the iMac placed with the CRT face down on a soft surface,
remove the bottom housing and the EMI cover to access the logic
board.
Testing J9 for +5 V Trickle Power on the Logic Board
You will need a volt meter to test for power on the logic board.
Refer to the picture on the next page to locate the necessary test
point referenced in the following procedure.
Plug in the computer, but leave the iMac powered OFF. Ground the
black probe on the volt meter to the logic board screw, as shown in
the photograph below. With one hand behind your back, touch the
red probe on the volt meter to the top pad (pin 1) at J9 (see the
photograph below) on the logic board, to see if you have +5V on
the logic board. A +5V reading on the logic board means the power
supply is providing the necessary trickle voltage to the logic
board.
Testing for +5 V Trickle Power at J9 on the Logic Board
Troubleshooting
Testing for Power - 8
Testing DCO (Down Converter On) Voltage at C4 on the Logic
Board
In a No Power situation, first check for +5 V trickle power at J9
(refer to “Testing J9 for +5 V Trickle Power on the Logic
Board”), then check the DCO (Down Converter On) voltage on the
logic board at capacitor C4 (see figure below).
The DCO voltage should be present as soon as the power cord is
plugged into the computer. Ground the black probe on the volt
meter to the logic board screw, as shown in the photograph below.
Touch the red probe to C10 (see the photograph below.) The DCO
voltage should measure approximately -1.2 volts with the power
cord plug plugged in. The voltage will jump to 21 volts after powering on the system. A reading of -1.2 volts up to +1 volt indicates the logic board is OK. Without a reading of -1.2 volts, verify
the fuse at F901 is OK (refer to “Testing the Power/Analog Board
Fuse” in this section). If the fuse is OK replace the power/analog/
video board.
Testing DCO Voltages at C4 on the Logic Board
Troubleshooting
Testing for Power - 9
Testing J7 for Voltage on the Logic Board
The following voltages measure if the down converter is providing
the required voltages and are only present if the system is powered on. If the following voltages are not correct, refer to the “No
Power” troubleshooting symptom chart.
Measure the following voltages at J7 on the logic board:
1.
Pin 2: +12 volts
2.
Pin 4: +5 volts
3.
Pin 14: +3.3 volts
Testing Voltages at J7 on the Logic Board
Troubleshooting
Testing for Power - 1 0
Testing the Power/Analog Board Fuse
First remove the bottom housing, front outer bezel, and the top
rear housing to access the power/analog board. The fuse is located
near the AC plug.
Warning: You must unplug the iMac to do a continuity test at the
power supply board fuse.
You will need an ohm meter to do a continuity test on the power
supply board fuse. Refer to the picture below to located the necessary test point referenced in the following procedure.
Unplug the computer to take this reading. Using an ohm meter,
touch the red and black probes to the two metal points at location
F901 and check for continuity (reading of “0”). If the ohm meter
registers “0”, the fuse is good. If the meter registers “infinite”,
the power/analog/video board should be replaced. A bad fuse is
indicative to a power/analog/video board problem. Note: To take
this reading, it’s easiest to insert the red probe of the meter
through the opening on the back side panel.
Testing Fuse 901 for Continuity
Troubleshooting
The PMU Chip - 1 1
The PMU Chip
The PMU (Power Management Unit) is a microcontroller 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: Be very careful when handling the main logic board.
Remove the battery when handling the logic board so the PMU is
not affected. 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 on the right side of the board, refer to the logic board diagram below.
iMac Logic Board Diagram
Troubleshooting
Resetting the PMU on the Logic Board - 1 2
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.
Disconnect the power cord and check the battery in the battery holder (BT1). The battery should read 3.3 to 3.7 volts.
If the battery is bad, replace the battery, wait ten seconds,
and then reset the PMU (refer to the next step). If the battery is good, go to the next step.
2.
Press the PMU reset switch (S1) once on the logic board and
then proceed to step 3. Do NOT press the PMU reset switch a
second time because it could crash the PMU chip.
3.
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 chart, “No Power” in this chapter.
4.
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.
Troubleshooting
Power-On Self Test - 1 3
Power-On Self Test
There is a power-on self test that resides in the ROM of the iMac.
This test automatically runs whenever the iMac 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 iMac 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 iMac
ships with PC-100 SDRAM and does not accept SDRAM SODIMMs or EDO memory).
Three Beeps: No RAM banks passed memory testing.
Four or Five Beeps: Bad checksum for the remainder of the
boot ROM. The ROM (which is located on the processor module)
is bad.
Troubleshooting
Logic Board Battery - 1 4
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 very sensitive
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 to 12:00 AM
1/1/04 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).
If the computer has a “No Power” situation, check the battery
before replacing modules. When checking the battery, make sure
the computer is unplugged. Measure the voltage across the battery’s BT1 positive and ground terminals. The battery should read
3.3 volts to 3.7 volts. If it’s lower than 3.2 volts, replace the
battery and reset the PMU chip.
Note: The iMac uses a lithium battery that must be disposed of in
accordance with hazardous waste regulations.
Troubleshooting
Ejecting a CD or DVD Disc, Part 1 - 1 5
Ejecting a CD or DVD Disc, Part 1
The CD/DVD eject mechanism is electrical rather than mechanical
on the iMac. If you wish to eject a bootable CD-ROM disc at
startup, simply hold down the mouse button until it ejects. If the
CD is not a bootable disc, simply wait for the iMac to boot and drag
the CD icon to the trash can.
If this fails to release the CD, there is an eject button which can be
activated by a small, blunt object such as a paper clip. The button
is located on the right side of the CD slot. Note that the power must
be on to eject a CD using this method. Note: Once you use the eject
button to eject a CD, you must restart the iMac in order to restore
functionality of the CD/DVD drive. If you don’t, you will not be
able to mount any subsequent discs that are inserted after you use
the emergency eject button.
If the CD/DVD discs still won’t eject after pressing the manual
eject button, remove the bottom housing, and then replace the
bottom housing ensuring that the center tab of the bottom housing
is properly aligned.
Troubleshooting
Ejecting a CD or DVD Disc, Part 2 - 1 6
Ejecting a CD or DVD Disc, Part 2
There are two internal levers on a slot-loading CD-DVD drive that
help center a CD-DVD disc. Some CDs and DVDs have and uneven
edge which can cause enough friction to prevent the disc from
ejecting. If this happens, follow these steps:
1 Take a large paperclip and unbend it so that you can insert it
into the CD/DVD slot (as shown below) about 1.5 inches from
the left edge of the slot.
2
With the other hand, drag the disc icon on the desktop to the
Trash to force the computer to eject the disc.
3
When you hear the disc attempt to eject, slide the paperclip to
the left edge of the slot and then remove the paperclip. You
should feel a little resistance from the spring loaded centering
lever. Once the disc has been successfully ejected, wipe the
outside edge of the CD/DVD with your hands. Cleaning the edge
of the disc in this way will reduce the likelihood of the disc
becoming stuck again.
Troubleshooting
HFS Plus Formatted Drives - 1 7
HFS Plus Formatted Drives
The hard drive in the iMac is formatted with HFS Plus (also
referred to as Mac OS Extended format). It is important to note
that Norton Utilities version 3.5 is not compatible with HFS Plus
(or Mac OS Extended format), and in fact, can destroy data on the
hard drive.
Norton Utilities version 3.5.3 or 3.5.2 will not attempt to repair
a drive formatted with Mac OS Extended format and versions 3.5.1
and earlier cannot recognize that a hard drive is in Mac OS
Extended format and can result in hard drive corruption and loss
of all data on the drive.
Note: When diagnosing hard drive problems, it is important to
verify whether or not the customer may have used the wrong disk
repair software for their drive before assuming that the problem
is hardware related.
If you experience problems with a hard drive that has been
formatted with HFS+, Apple Computer recommends using Disk
First Aid (which is included on the system software CD that ships
with the iMac). Disk First Aid can be used to recover data that may
have been deleted by Norton Utilities. (See the Symantec Web site
at http://www.symantec.com/nu/num-hfs.html for more
information on Norton Utilities and Mac OS Extended format.)
Some other disk utility and disk locking programs are
incompatible with Mac OS Extended format. Before you attempt to
use a disk utility or disk locking program, make sure the version
you have is compatible with Mac OS Extended format. Check the
documentation that came with the program or contact the
manufacturer or the vendor that supplied the program.
Use the Get Info command to determine how a hard drive has been
formatted. Drives formatted with HFS will appear as “Mac OS
Standard”, while drives formatted with HFS+ will appear as “Mac
OS Extended.”
For more information on HFS Plus formatting of hard drives,
refer to the Technical Info Library, article # 30344.
Troubleshooting
Testing the Modem - 1 8
Testing the Modem
The iMac ships with AppleWorks software, which can be used to
test the iMac modem connection. You should run this test if the
modem is not able to dial out. To perform this test:
1. Locate and launch AppleWorks.
2. From the AppleWorks New Document window, select
Communications and click OK. You will be presented with an
untitled communications document.
3. Click on the settings menu item and select Connection from the
menu, which will bring up a new window. This window allows
you to select the communications toolbox device to access the
modem.
4. Click and hold the menu next to Method and select the Serial Tool
from the options presented.
5. Click on the Internal Modem setting under the Current Port
setting. After selecting the port, click the OK button. (You can
ignore the rest of the settings.)
6. Open the serial port by selecting Open Connection from the
Session menu.
7. Type “AT” into the Communications document. The modem
should respond with an OK message.
This procedure verifies that the program is connecting with the
modem and that the modem is responding.
Troubleshooting
Testing the Modem - 1 9
A good test to see if the phone line is working is to type “ATDT”,
which will open the phone line. If the modem reports NO DIALTONE, there isn't a valid analog line connected. If the phone line
works, you will hear a dial tone until you press the Return key, at
which time the modem will report NO CARRIER. A No Carrier
message means the phone line was successfully opened.
Other things that can be done here are:
•
Call another modem to verify connections.
•
Call a working phone number to see if you can successful
connect to an outside line.
•
Use the ATI1-17 commands to check firmware versions and
modem features.
•
Use ATZ to reset the modem back to its original configuration.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
Symptom/Cure Tables: Startup Problems
Before the Finder Appears
If you have trouble starting up the iMac, and the problem occurs
before the Finder appears on the screen, you may have either a
software or a hardware problem.
Following are troubleshooting tables with problem symptoms that
you may see before the Finder appears. Possible causes for each
symptom can be found in the left-hand column with the corresponding fixes in the right-hand column. The troubleshooting
information is presented in the order of the most probable cause
and fix; therefore, Apple strongly recommends that you carry out
the troubleshooting in the order in which it is presented.
Note: If you are instructed to replace a module and this does not fix
the problem, be sure to reinstall the original module before you
proceed to the next fix.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
No Power
In a “No Power” situation, the system is completely dead. There is no LED, no hard
drive power, and the screen is completely black. (Refer to “Testing for Power” earlier in this chapter for instructions on how to test for power at each component referenced in this procedure.)
Possible Cause
Possible Fix
Bad power cord, connection, or outlet.
- Verify the power outlet is good.
- Try a known-good power cord to determine if the
existing power cord could be the problem. Make sure
the power cord is connected securely at both ends.
Improperly aligned front
power-on button
-If the front power-on LED is not centered properly
within the inner button, the inner power button can
become stuck between the LED and the inner bezel
resulting in a no power, intermittent shut down, or
sleep situation. Refer the LED Alignment procedure in
the Adjustments chapter or to Kbase/TIL article
58622 for steps to resolve the LED alignment issue.
Bad USB keyboard.
- Verify the keyboard cable is connected properly to the
computer.
- Disconnect the keyboard and power on the system via
the button on the front of the computer. Do you have
power to the system now?
Yes: The keyboard is bad. Replace the keyboard.
No: Go to next step.
The PMU chip needs to be
reset.
- Press the PMU chip on the logic board with the AC
power cord disconnected. (See “The PMU Chip” and
“Resetting the PMU on the Logic Board” mentioned
earlier in this chapter.)
- Connect the power cord and power on the system again.
Do you have power to the system now?
Yes: Test the unit with MacTest Pro and return the
computer to the customer.
No: With the AC power cord connected, reset the PMU
chip again. Do you have power to the system now?
Yes: The battery is likely bad, check the battery.
No: Go to the next step.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
In a “No Power” situation, the system is completely dead. There is no LED, no hard
drive power, and the screen is completely black. (Refer to “Testing for Power” earlier in this chapter for instructions on how to test for power at each component referenced in this procedure.)
Possible Cause
Possible Fix
Bad power/analog/video
board
-Verify the fuse at F901 on the power/analog board is
good. (Refer to “Testing for Power at the Power/
Analog Board Fuse” mentioned earlier in this
chapter.) Did you get a “0” reading?
Yes: Check/reseat all power/analog/video board cable
connections. Make sure the video board is securely
attached to the CRT neck. If the No Power problem
persists, go on to the next step.
No: Replace the power/analog/video board.
Bad power/analog/video
board
- Check for trickle power on the logic board (Refer to
“Testing J9 for +5 V Trickle Power on the Logic
Board” mentioned earlier in this chapter). Trickle
power is present as soon as the power cord is plugged
into the computer.
Did you measure +5 V trickle power on pin 1 of
connector J9?
Yes: Go to the next step.
No: Replace the power/analog/video board.
Bad down converter board
- Check for DCO voltage at location C4 on the logic board
(Refer to “Testing DCO (Down Converter On) Voltage
at C4 on the Logic Board”) mentioned earlier in this
chapter). Did you measure approximately
-1.2 volts?
Yes: Go on to the next step.
No: Replace the down converter board.
Bad LED Power Switch
Board
- Replace the LED/power switch board (922-4160).
If that doesn’t solve the problem, go on to the next step.
Bad Power/Analog board
- Replace the power/analog/video board
Bad logic board
- Replace the logic board.
Bad CRT
- Replace the CRT.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
No Video or Unstable Raster
Normal startup boot chime, the LED is on, and the hard drive starts up. The display,
however, is solid gray.
Possible Cause
Possible Fix
Corrupted PRAM.
- Reset parameter RAM. Hold down <Command> <Option>
<P> <R> during startup before “Welcome to Macintosh” appears.
Corrupted system software.
- Boot off the system CD that came with the unit. Do you
see a normal screen display now?
Yes: Reinstall system software. (You must use the
system software CD that came with the unit to get the
correct version of Mac OS.)
No: Go to next step.
The PMU chip or logic
board needs to be reset.
- Press the PMU chip on the logic board with the AC
power cord disconnected. (See “The PMU Chip” and
“Resetting the PMU on the Logic Board” mentioned
earlier in this chapter.)
- Connect the power cord and power on the system again.
Do you have power to the system now?
Yes: Test the unit with MacTest Pro and return the
computer to the customer.
No: Plug in the AC power cord and reset the PMU chip
again. Do you have power to the system now?
Yes: The battery is likely bad, check the battery.
No: Go to the next step.
Bad video cable connection.
- Verify that the CRT video board cables, the RGB cable,
and P701 (the deflection yoke cable on the power/
analog board) are securely attached. If the problem
persists go on to the next step.
Bent CRT neck pins.
- Remove the CRT video board. Check that the pins on the
CRT neck are not bent. Carefully reseat the CRT video
board and power on the computer. Do you have video
now?
Yes: Run MacTest Pro and return the computer to the
customer.
No: Go on to the next step.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
Normal startup boot chime, the LED is on, and the hard drive starts up. The display,
however, is solid gray.
Possible Cause
Possible Fix
Bad power/analog/video
board
- Check for trickle power on the logic board (Refer to
“Testing J9 for +5 V Trickle Power on the Logic
Board” mentioned earlier in this chapter). Trickle
power is present as soon as the power cord is plugged
into the computer.
Did you measure +5 V trickle power on pin 1 of
connector J9?
Yes: Go to the next step.
No: Refer to the troubleshooting symptom “No Power”.
Bad logic board
Check for DCO voltage at location C4 on the logic board
(Refer to “Testing DCO (Down Converter On) Voltage
at C4 on the Logic Board”) mentioned earlier in this
chapter). Did you measure approximately
-1.2 volts?
Yes: Go to the next step.
No: Replace the logic board.
Bad internal RGB video
cable.
- Replace the internal RGB video cable that attaches to
the power/analog/video board and to the logic board.
The cable is screwed to the power/analog board,
located near the AC power plug on the power/analog
board.
- If this doesn’t solve the problem, go to the next step.
Bad power/analog/video
- Replace the power/analog/video board.
Bad CRT.
- Replace the CRT.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
Gray Screen
In a “Gray Screen Raster” situation, you will get a normal startup boot chime and the
system will have a green LED. The display, however, will have a solid gray screen with
no cursor or desktop displayed.
Possible Cause
Possible Fix
Corrupted system software.
- Boot off the system CD that came with the unit. Do you
see a normal screen display now?
Yes: Reinstall system software. (You must use the
system software CD that came with the unit to get the
correct version of Mac OS.)
No: Go to next step.
The PMU chip or logic board
needs to be reset.
- Press the PMU chip on the logic board with the AC
power cord disconnected. (See “The PMU Chip” and
“Resetting the PMU on the Logic Board” mentioned
earlier in this chapter.)
- Connect the power cord and power on the system again.
Do you have power to the system now?
Yes: Test the unit with MacTest Pro and return the
computer to the customer.
No: Plug in the AC power cord and reset the PMU chip
again. Do you have power to the system now?
Yes: The battery is likely bad, check the battery.
No: Go to the next step.
Bad video cable connection.
- Verify that the CRT video board and video board cables
going to and from the power/analog board are securely
attached. If the problem persists go on to the next step.
Bad SDRAM
- Reseat/replace the SDRAM with known-good SDRAM.
Bad logic board
- Replace the logic board.
Bad power/analog/video
board
- Replace the power/analog/video board.
Bad CRT
-Replace the CRT.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
Error Beep(s)
If you hear from one to five error beeps at startup with no boot chime, you have a
hardware problem. The table explains how to troubleshoot and repair an iMac unit
that sounds one or more error beeps at startup.
Possible Cause
Possible Fix
No DRAM is installed or
detected.
Do you hear one error beep at startup?
Yes: Follow these steps to resolve the problem:
1. Make sure the DRAM are PC-100 SDRAM. Reseat
the SDRAM and try again.
2. If no SDRAM is present, install a known-good
PC-100 SDRAM and try again.
3. If DRAM is present, replace DIMM one at a time,
with a known-good PC-100 SDRAM.
No: Go to next step.
Incompatible RAM is
installed.
Do you hear two error beeps at startup?
Yes: Verify that only SDRAM PC-100 DIMMs are
installed (The iMac ships with PC-100 SDRAM
memory and is not compatible with EDO
DIMMs.)
No: Go to next step.
Bad RAM.
Do you hear three error beeps at startup?
Yes: Replace the existing SDRAM one DIMM at a time
with known-good PC-100 SDRAM.
No: Go to next step.
Bad ROM.
Do you hear four or five error beeps at startup?
Yes: Replace the logic board.
No: If you do not hear any error beeps at startup, you
have a different problem and should refer to one of the
other troubleshooting tables in this chapter.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
Flashing Question Mark
This problem refers to a flashing question mark that appears on the screen during
startup.
Possible Cause
Possible Fix
Corrupted system software or software drivers.
Boot from the system CD that came with the unit. Can you
see the hard drive on the desktop?
Yes: The system software is most likely the problem.
Reinstall system software. (You must use the system
software CD that came with the unit to get the correct
version of Mac OS with the appropriate iMac
enablers.)
No: The hard drive or its software drivers are most
likely the problem. Can you see the hard drive using
Drive Setup?
Yes: Use Drive Setup to reinstall the software
drivers for the hard drive. If the problem persists,
use Drive Setup to reinitialize the hard drive (See
Kbase/TIL article #22206 for Drive Setup
information.)
Warning: You will lose all data on the hard drive
when you reinitialize it. Backup the data first if
possible.
No: Go to next step.
Bad cable connections, or
bad hard drive.
If you don’t see the hard drive using Drive Setup:
1. Check all cable connections to and from the hard drive.
2. Replace the HD/CD/DVD data cable.
3. Replace the hard drive.
4. Replace the hard drive power cable.
5. Replace the logic board.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
System Hangs During Boot
This problem refers to a system that begins a normal startup process with a boot
chime and normal display, but then freezes before the Finder appears.
Possible Cause
Possible Fix
System extensions causing
a conflict.
Boot with Extensions off by holding down the Shift key
during startup. (See Kbase/TIL article #14343 for
more information on possible Extension conflicts.)
Does the system startup successfully with Extensions
off?
Yes: Begin adding back the system Extensions one at a
time and starting up the system after each addition. If
the system freezes again, you know that the last
Extension you added is causing the problem.
No: Go to the next step.
Corrupted system software or bad SDRAM.
Boot from the system CD that came with the unit. Does
the system startup successfully?
Yes: Reinstall system software. (You must use the
system software CD that came with the unit to get the
correct version of Mac OS.)If the problem persists, go
to the next step.
No: Reseat the SDRAM. If the problem persists,
replace the SDRAM (one DIMM at a time) with knowngood PC-100 SDRAM.
Bad hard drive.
Can you see the hard drive using Drive Setup?
Yes: Use Drive Setup to reinstall the software
drivers for the hard drive. If the problem persists,
use Drive Setup to reinitialize the hard drive.
(See Kbase/TIL article #22206 for Drive Setup
information.) Warning: You will lose all data on
the hard drive when you reinitialize it. Back up the
data first if possible.
No: Go to next step.
Bad hard drive, cables, or
cable connections.
If you don’t see the hard drive using Drive Setup:
1. Check all cable connections to and from the hard drive.
2. Replace the HD/CD/DVD data cable.
3. Replace the hard drive.
4. Replace the hard drive power cable.
5. Replace the logic board.
If the problem persists, go on to the next step.
Troubleshooting
Symptom/Cure Tables: Startup Problems Before the Finder
This problem refers to a system that begins a normal startup process with a boot
chime and normal display, but then freezes before the Finder appears.
Possible Cause
External device is bad.
Possible Fix
Disconnect all external devices (USB and Ethernet). Then
begin reconnecting these devices one at a time
(beginning with the keyboard and then the mouse) and
start up the computer after each device is connected to
see if one of the external devices is causing the
problem. If the problem occurs after you connect a
particular external device, replace the device in
question.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 0
Symptom/Cure Tables: System Problems
After Startup
If you experience system problems after a successful startup
(i.e., after the Finder appears on the screen), most likely the
problem is not with the iMac hardware (with the exception of
some possible RAM issues).
Following are troubleshooting tables with problem symptoms that
you may see after the Finder appears. Possible causes for each
symptom can be found in the left-hand column with the corresponding fixes in the right-hand column. The troubleshooting
information is presented in the order of the most probable cause
and fix; therefore, Apple strongly recommends that you carry out
the troubleshooting in the order in which it is presented.
Note: If you are instructed to replace a module and this does not fix
the problem, be sure to reinstall the original module before you
proceed to the next fix.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 1
System Hangs
Refer to this table if your system intermittently hangs (freezes) during normal operation. Note: if your system only hangs when using a specific application, the problem
is most likely with the application and not with your iMac hardware or system software. If this table does not solve the problem, refer to the “Software Troubleshooting”
manual on Service Source (under the Troubleshooting tab) for more comprehensive
information.
Possible Cause
Possible Fix
System Extensions causing
a conflict.
Boot with Extensions off by holding down the Shift key
during startup. (See Kbase/TIL article #14343 for
more information on possible Extension conflicts.)
Does the system startup successfully with Extension
off?
Yes: Begin adding back the system Extensions one at a
time and starting up the system after each addition. If
the system freezes again, you know that the last
Extension you added is causing the problem.
No: Go to the next step.
Corrupted system software.
Boot from the system CD that came with the unit. Does
the problem recur?
Yes: Go to next step.
No: The system software is most likely the problem.
Reinstall system software. (You must use the system
software CD that came with the unit to get the correct
version of Mac OS.)
Bad USB device.
Turn off the computer and disconnect all USB devices.
Next, power on the system using the power button on
the front of the unit, and begin adding back the USB
device one at time, beginning with the keyboard and
then the mouse, and so on. If the system hangs only
after you reconnect a particular USB device, replace
that USB device.
Bad memory.
Run MacTest Pro in loop mode overnight to test for bad
memory. If MacTest Pro finds a bad memory module,
or other hardware, replace the hardware in question
with a known-good module.
Bad logic board.
Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 2
Distorted Video
Distorted Video refers to a problem with the screen geometry or focus.
Possible Cause
Possible Fix
System is out of focus.
Adjust the focus using the Display Adjustment Utility on
the MacTest Pro CD. (See “Focus” in the iMac
Adjustments chapter for instructions.)
Screen geometry is out of
adjustment (display is off
center, sides or top of the
screen are not straight,
etc.).
Adjust the screen geometry using the Display Adjustment
Utility on the MacTest Pro CD. (See “Geometry” in the
iMac Adjustments chapter for instructions.)
Screen cutoff or white balance is out of adjustment.
Adjust the cutoff or white balance using the Display
Adjustment and Display Service Utilities on the MacTest
Pro CD. (See “Video” in the iMac Adjustments chapter
for instructions.)
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 3
Thin White Line
A a thin, white horizontal line scrolls from top to bottom, or bottom to top on the iMac
display.
Possible Cause
Possible Fix
Display may need adjusting.
Adjust the cutoff or white balance using the Display
Adjustment and Display Service Utilities on the MacTest
Pro CD. (See “Video” in the iMac Adjustments chapter
for instructions.)
Power/analog/video board
is faulty
Replace the power/analog/video board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 4
Tinting Video
Tinting Video refers to a predominant color tint or color covering the screen.
Possible Cause
Possible Fix
Environmental causes.
Verify that the iMac unit is not near other equipment
(such as speakers, radios, phones, fluorescent lighting,
magnets, or other electronic equipment) that could affect
the video display. If necessary, move the iMac computer
to another area and restart the unit.
Loose video cables.
Reseat the video cables connecting from the power/analog
board to the video board. Make sure that both ends of the
cable are firmly seated into their connectors.
Loose video board.
Reseat the video board on the CRT neck. Make sure the
CRT neck screw is secure.
Color is out of adjustment.
Adjust the white balance using the Display Adjustment
and Display Service Utilities on the MacTest Pro CD.
(See “Video” in the iMac Adjustments chapter for
instructions.)
Bad power/analog/video
board.
Replace the power/analog/video board.
Bad RGB video cable.
Replace the internal RGB video cable that runs between
the power/analog board and the P301 and P302 on the
video board.
Bad Logic Board.
Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 5
Garbage Video
Garbage video refers to erroneous text or characters that appear on the screen.
Possible Cause
Possible Fix
Corrupted system software.
Boot from the system CD that came with the unit. Open
the Monitors and Sound control panel and change the
Maximum Resolution and Color Depth to their maximum
settings. Restart the unit. Does the screen display appear
normal now?
Yes: Reinstall system software. (You must use the
system software CD that came with the unit to get the
correct version of Mac OS.) If the problem persists, go
to the next step.
No: Go to next step.
Bad logic board.
Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 6
Intermittent Shut Down or Sleep
An iMac with a sticking power button can generate unpredictable behavior. The iMac
randomly shuts itself off or puts itself to sleep. The iMac will not start up from either
the front power button or the keyboard.
Possible Cause
Improperly aligned front
power-on button
Possible Fix
-If the front power-on LED is not centered properly
within the inner button hole, the power button can
become stuck between the LED and the inner bezel
resulting in a no power, intermittent shut down, or
sleep situation. Refer the LED Alignment procedure in
the Adjustments chapter or to Kbase/TIL article
58622 for steps to resolve the LED alignment issue.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 7
Memory Error Dialog
If you see a error dialog message pertaining to memory after you have a successful
startup sequence (that is, a normal boot tone with no error beeps and proper video
display, etc.) then refer to the table below to troubleshoot the problem.
Possible Cause
Dialog message reads “The
built-in memory test has
detected a problem. Please
contact a service provider
for assistance.”
Possible Fix
Run Mac TestPro to locate the bad SDRAM. Replace the
SDRAM with a known-good PC-100 SDRAM DIMM.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 8
Can’t Wake From Sleep
The computer cannot be brought out of “sleep” mode by pressing a key on the keyboard.
The problem is usually evident by a black screen and a pulsing amber LED.
Possible Cause
Possible Fix
PMU
Press the PMU chip on the logic board with the AC
power cord disconnected. (See “The PMU Chip” and
“Resetting the PMU on the Logic Board” mentioned
earlier in this chapter.)
Connect the power cord and power on the system again.
Do you have power to the system now?
Yes: Test the unit with MacTest Pro and return the
computer to the customer.
No: Plug in the AC power cord and reset the PMU chip
again. Do you have power to the system now?
Yes: The battery is likely bad, check the battery.
No: Go to the next step.
Bad keyboard
Try a known-good keyboard.
Corrupted PRAM
Reset the PRAM by holding down the Option–Command–
P–and R keys
Software Conflict
Reinstall System Software. You must use the system
software that came with the unit in order to get the
correct version of Mac OS. Note: If the computer
sleeps while connected to the Internet, and is running
Mac OS 8.6 or Mac OS 9.0, download Apple Audio
Update 1.3 from the Apple Software Update page.
Bad logic board
Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 3 9
Network Problems
Refer to this troubleshooting table if you are unable to switch to the Ethernet network
option in the control panel or if you are unable to see any network devices. Note: if you
are able to see most network devices, but one particular device does not show up in the
Chooser, troubleshoot the device in question. You most likely do not have a network
problem.
Possible Cause
Possible Fix
Wrong option selected in
the Control Panel.
Open the Network control panel and select the Ethernet
option. Are you able to select the Ethernet option?
Yes: Verify that you can now see devices on the
network. If the problem persists, go to the next step.
No: Go to next step.
Corrupted PRAM.
Reset parameter RAM. Hold down Command >Option> <P>
<R> during startup but before “Welcome to Macintosh”
appears.
Corrupted system software.
Boot from the system CD that came with the unit. Open
the Network control panel and switch to Ethernet. Are
you able to switch to Ethernet and see Ethernet devices
on the network now?
Yes: Reinstall system software. (You must use the
system software CD that came with the unit to get the
correct version of Mac OS.) If the problem persists, go
to the next step.
No: Go to next step.
Bad Ethernet cable.
Replace the Ethernet cable with a known-good cable.
Bad Ethernet port at the
wall or hub.
Try connecting to a different Ethernet port at the wall or
external hub. Are you able to switch to Ethernet and
see Ethernet devices on the network now?
Yes: The original Ethernet port is bad. Contact your
network administrator.
No: Go to next step.
The entire network is
down.
Are other users experiencing the same problem?
Yes: There is a network-wide problem. Contact your
network administrator.
No: Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 0
CD_ROM or DVD-ROM Vibration
CD-ROM or DVD-ROM vibration is typically caused by unbalanced discs when spinning
at higher speeds in the internal CD-ROM or DVD-ROM drive. This vibration may cause
the drive to have difficulty reading the disc.
Possible Cause
Bad CD-ROM or DVD-ROM
disc.
Possible Fix
Try using a known-good compact disc.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 1
CD-ROM or DVD-ROM Won’t Eject
CD-ROM or DVD-ROM disc won’t eject from the slot.
Possible Cause
Bad CD-ROM or DVD-ROM
disc.
Possible Fix
1
Press and hold down the mouse button on startup.
Note: This only works on iMac computers with Boot
ROM version 2.3 or higher. To check the Boot ROM
version, open Apple System Profiler/System Profile
tab/Production information/Boot ROM Version.
2
Try manually ejecting the disc. Push a paper clip
through the manual eject hole located on the right
side of the CD/DVD slot. Refer to “Ejecting a CD or
DVD Disc, Part 1 earlier in this chapter”.
3
Restart the iMac after the disc ejects. If you don’t
restart, you will not be able to mount any subsequent
discs that are inserted after you use the manual eject
button.
Note: The power must be on to eject a CD or DVD disc.
If this doesn’t solve the problem, continue with the
procedures on the next page.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 2
CD-ROM or DVD-ROM disc won’t eject from the slot.
Possible Cause
Uneven edge of the CD or
DVD drive.
Possible Fix
There are two internal levers on a slot-loading CD-DVD
drive that help center a CD-DVD disc. Some CDs and DVDs
have and uneven edge which can cause enough friction to
prevent the disc from ejecting. If this happens, follow
these steps:
1 Take a large paperclip and unbend it so that you can
insert it into the CD/DVD slot (as shown below)
about 1.5 inches from the left edge of the slot.
2
With the other hand, drag the disc icon on the desktop
to the Trash to force the computer to eject the disc.
3
When you hear the disc attempt to eject, slide the
paperclip to the left edge of the slot and then remove
the paperclip. You should feel a little resistance from
the spring loaded centering lever. Once the disc has
been successfully ejected, wipe the outside edge of the
CD/DVD with your hands. Cleaning the edge of the disc
in this way will reduce the likelihood of the disc
becoming stuck again.
Bottom housing not aligned
properly.
Remove the bottom housing, and then replace the bottom
housing. Ensure the tabs on the bottom housing align with
the tab slots on the front outer bezel. Pay particular
attention to the alignment of the center tab. Refer to the
take-apart procedures for removing and reseating the
bottom cover.
Bad CD-ROM or DVD-ROM
drive.
Replace CD/DVD drive mechanism.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 3
CD-ROM or DVD-ROM Not Showing on Desktop
CD-ROM and DVD-ROM problems are defined by the inability to see the CD or DVD on
the desktop or to open a CD or DVD that is loaded into the drive.
Possible Cause
Possible Fix
Bad CD-ROM or DVD-ROM
disc.
Try using a known-good compact disc.
CD-ROM or DVD-ROM disc
didn’t load properly.
Manually eject the disc and try again. Push a paper clip
through the manual eject hole located on the right side of
the CD/DVD slot. Restart the iMac after the disc ejects.
Note: The power must be on to eject a CD or DVD disc.
Corrupted system software
If the CD-ROM or DVD-ROM drive fails to mount, boot off
the system CD that came with the unit. Do you see the
CD-ROM or DVD-ROM drive on the desktop now?
Yes: Reinstall system software. (You must use the system software CD that came with the unit to get the correct version of the Mac OS.)
No: Go to the next step.
Master/Slave switch set
incorrectly on the back of
the CD-ROM or DVD-ROM
drive.
Make certain the Master/Slave switch (located under the
CD Adapter board) on the drive is set to Slave. The Slave
position is the switch closest to the CD Adapter connector
on the back of the CD-ROM or DVD-ROM drive. The
switch is set correctly at the drive vendor, but it may
have been moved by mistake.
Loose cable.
Check all cables running to and from the CD-ROM or
DVD-ROM drive at both ends and make sure they are
attached securely.
Bad CD-ROM or DVD-ROM
drive.
Replace CD-ROM or DVD-ROM drive.
Bad HD/CD/DVD data cable.
Replace the HD/CD/DVD data cable.
Bad logic board.
Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 4
Hard Drive Problems
Hard drive problems include a hard drive that doesn’t operate (it doesn’t spin) or a
hard drive that doesn’t mount (it doesn’t appear on the desktop).
Possible Cause
Possible Fix
Corrupted drivers.
Can you see the hard drive using Drive Setup?
Yes: Use Drive Setup to reinstall the software
drivers for the hard drive. If the problem persists,
use Drive Setup to reinitialize the hard drive.
(See Kbase/TIL article # 22206 for instructions.)
Warning: You will lose all data on the hard drive
when you reinitialize it. Backup the data first if
possible.
No: Go to next step.
Bad hard drive, cables, or
cable connections.
If you don’t see the hard drive using Drive Setup:
1. Check all cable connections to and from the hard drive.
2. Replace the HD/CD/DVD data cable.
3. Replace the hard drive.
4. Replace the hard drive power cable.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 5
Sound Out Problems
Sound out problems refer to a lack of sound coming from the internal speakers (located
on the front of the unit directly below the display), external speakers (connected via
the I/O panel to the speaker connector on the logic board), or both.
Possible Cause
Possible Fix
Control Panel setting is
incorrect.
First, disconnect any external microphones, speakers or
headphones. Next, verify that volume setting in Control
Panel is adequate and that mute is not checked. Test the
for sound coming from the internal speakers. Do you
have sound now?
Yes: If the initial sound out problem was with the
internal speakers, the problem is solved. If you
reconnect the external sound out device and it is not
working, the problem may be with the external device
itself or its cable. Replace the external microphone,
speaker, or headphone in question with a known-good
device. If the problem persists, replace the logic
board.
No: Go to next step.
Corrupted PRAM.
Reset parameter RAM. Hold down <Command> <Option>
<P> <R> during startup but before “Welcome to Macintosh” appears.
Loose speaker connection.
Verify that both ends of the internal speaker cables are
attached securely.
Loose audio cable.
- Reseat the audio cable (922-4039) located on the
divider panel, under the CRT.
Bad audio cable.
- Replace the audio cable (922-4039).
Bad speakers.
- Replace the speakers.
Bad logic board.
Plug known-good headphones or external speakers into
the external jack. Do you get sound?
Yes: Go to next step.
No: Replace the logic board.
Bad headphone board.
- Replace the headphone board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 6
Sound In Problems
Sound in problems involve the internal microphone. Symptoms could be: audio recording quality is poor, a high level of background noise is noticeable, or no sound is
recorded.
Possible Cause
Possible Fix
Sound control panel.
Open the Simple Sound Control Panel (found under the
Apple Menu). Select CD Quality under the Sound menu to
minimize noise on the internal microphone. Did this
solve the problem?
Yes: If the initial sound in problem was with the
sound control panel; the problem is solved.
No: Go to next step.
Loose audio cable.
Reseat the audio cable (922-4039).
Bad audio cable.
Replace the audio cable (922-4039).
Bad microphone.
Replace the internal microphone.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 7
Noise From Computer After Shutdown
After the computer is shutdown, the computer emits a loud humming or buzzing noise
that may continue for minutes or until the power cord is removed.
Possible Cause
Logic Board
Possible Fix
Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 8
USB Problems
USB problems refer to symptoms or issues that may occur with external USB devices
that are attached to the iMac. This could include Apple and/or third-party USB devices.
Possible Cause
Possible Fix
Not enough power for the
USB device to function.
The following error message will appear confirming that
a device cannot function at all due to a lack of power. This
lack of power (depending on the device) can be a result of
a disconnected external power source, or not enough
power available from the hub the device is connected to.
The two corrective steps listed in the dialog box (shown
on the next page) provide the user guidance in
troubleshooting these conditions.
USB device experiencing a
partial lack of power.
Similar to the first error message, this error message indicates
a device may not completely function due to a partial lack of
power and gives steps to remedy the problem.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 4 9
USB problems refer to symptoms or issues that may occur with external USB devices
that are attached to the iMac. This could include Apple and/or third-party USB devices.
Possible Cause
Possible Fix
USB driver missing.
This error message indicates the device's driver is
missing. Customers will need to check the instructions
that came with the device and install the Mac OS driver.
Bad USB connector.
Connect the problem device directly into one of the iMac
USB ports or, if it’s already connected to one of the
iMac USB ports, switch it to the other port.
Bad USB device.
Replace the USB device.
Bad logic board.
Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 0
Cursor Problems
This section deals with a cursor that moves on the screen, but clicking the mouse has
no effect or double-clicking the mouse does not open an application, disk or server.
Possible Cause
Possible Fix
Corrupted PRAM.
Reset parameter RAM. Hold down <Command> <Option>
<P> <R> during startup but before “Welcome to Macintosh” appears.
Corrupted system software.
Boot off the system CD that came with the unit. Does the
cursor work now?
Yes: Reinstall system software. (You must use the
system software CD that came with the unit to get the
correct version of Mac OS.)
No: Go to next step.
Bad USB port on the keyboard.
If the mouse is connected to the keyboard, connect the
mouse to one of the USB ports inside the iMac I/O panel
instead. Does the cursor work now?
Yes: Replace the keyboard.
No: Replace the mouse.
Bad USB port on the iMac.
If the mouse is already connected to one of the USB ports
inside the iMac I/O panel, switch it to the other USB
port. Does the cursor work now?
Yes: Replace the logic board.
No: Go to next step.
Bad mouse.
Replace mouse.
Bad logic board.
Replace logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 1
USB Printer Problems
This troubleshooting table deals with an iMac that cannot print to an attached, knowngood USB printer.
Possible Cause
Possible Fix
Printer is not compatible
with the iMac USB bus.
Verify with the manufacturer of the printer that it is
iMac compatible.
Chooser is set incorrectly.
Open the Chooser and verify that you have the correct
printer and printer driver selected.
Bad printer driver or
hardware problem.
Use Apple System Profiler to see if it recognizes that a
USB printer is connected.
Yes: Reinstall the printer driver.
No: The printer or its cable is malfunctioning. Replace
the cable or printer.
Bad external USB port.
If the printer is connected to a third-party hub, switch
it to one of the iMac ports in the I/O panel. Does the
printer work now?
Yes: You have a bad third-party hub. Replace the
device that contains the problem USB port or refer to
the third-party documentation for troubleshooting
procedures.
No: Go to next step.
Bad USB port on the iMac.
If the printer is already connected to a USB port on the
iMac, switch it to the other USB port. Does the printer
work now?
Yes: Replace the logic board.
No: Go to next step.
System software is corrupted.
Perform a clean install of the system software using the
Mac OS CD that shipped with the iMac. (You must use the
system software CD that came with the iMac in order to
get the correct version of Mac OS 8.1 with the appropriate iMac enablers.)
Bad cable.
Replace the printer interface cable.
Bad logic board.
Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 2
Networked Printer Problems
This troubleshooting table deals with an iMac that cannot print to an attached, knowngood networked printer.
Possible Cause
Possible Fix
Bad network connections.
Check the network connections.
Wrong version of system
software is installed.
Verify that you have the correct version of Mac OS. If you
are unsure, reinstall the system software using the
original CD that shipped with the iMac unit.
Chooser is set incorrectly.
Open the Chooser and verify that you have the correct
printer and printer driver selected.
System, network, or
printer software is corrupted.
Perform a clean install of the system software (you must
use the system software CD that came with the iMac in
order to get the correct version of Mac OS with the
appropriate iMac enablers) and/or the network and
printer software.
General network problems.
Refer to the “Network Problems” troubleshooting table
earlier in this chapter.
Bad logic board.
Replace the logic board.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 3
Modem Not Recognized
This table should help you troubleshoot and fix problems when the internal modem is
not recognized. Follow the instructions under the “Possible Fix” column to resolve the
problem.
Possible Cause
Possible Fix
Modem Is Not Recognized: If the modem is not recognized or listed in the application or
OS, refer to this section of the table.
Needed extensions or CCL
files are not installed or
are corrupt.
Are the correct CCL and extension files installed? (Note:
You will need the iMac Modem Extension and the iMac
internal modem CCL.)
Yes: The CCL or extension may be corrupt. Reinstall
the CCL and modem extension. If the problem persists,
reinstall the system software and try again.
No: Install the correct CCL and modem extension and
try again.
PRAM is corrupt.
Zap PRAM by holding down Option, Command– P–and R
keys.
Serial Port Not Available message: If the Modem Control Panel and/or AppleWorks
reports that the serial port is not available, refer to this section of the table.
The modem is loose, missing, or bad.
Is the modem installed?
Yes: Reseat the modem and try again. If the
problem persists, replace the modem board.
No: Install a modem and try again.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 4
Modem Dialing Problems
If the modem is having problems dialing out, refer to the table below for possible fixes.
The table is divided into different sections, each with its own symptom and cure(s).
Find your symptom and then follow the instructions under the “Possible Fix” column
to resolve the problem. Note: A good first step in troubleshooting a modem problem is
to verify the modem connection as explained in “Testing the Modem” earlier in this
chapter.
Possible Cause
Possible Fix
No Dial Tone: If the system gives you a No Dial Tone error message, refer to this section of the table.
The phone line is not connected.
Is the phone line connected securely to the computer and
to the wall jack?
Yes: Go to the next step.
No: Reconnect the phone line at both ends and try again.
The phone line is dead.
Plug a phone into that line. Do you get a dial tone?
Yes: There does not appear to be a problem with the
phone line. Test the modem as explained in “Testing
the Modem” earlier in this chapter.
No: Report the dead phone line to the phone company.
There is a problem with
the modem.
Reseat the modem. If the problem persists, replace the
modem.
Modem Cannot Dial Out: If there is a dial tone, but the user cannot dial out with the
modem, refer to this section of the table.
The modem settings are
incorrect.
Open the modem control panel and make sure the modem
type selected is iMac Internal 56K, (or Apple iMac
internal modem in the Earthlink setup screen) the sound
is On, and the dialing is set to Tone. At this point, leave
the ignore dial tone setting unselected.
The incorrect CCL file is
selected or it is damaged.
Verify you have the correct CCL selected. If the problem
persists, reinstall the CCL file.
There is a problem with
the phone line or dial tone
settings.
Can you get a normal dial tone with the modem?
Yes: Go to the next step.
No: Some voice mail systems use a beeping dial tone to
notify the user of waiting messages, which can affect
the modem connection. Open the modem control panel
and select Ignore Dial Tone.
The modem is loose or
missing.
If you get an error message that the modem is not found,
verify that the modem is installed and properly seated. If
the problem persists, replace the modem.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 5
If the modem is having problems dialing out, refer to the table below for possible fixes.
The table is divided into different sections, each with its own symptom and cure(s).
Find your symptom and then follow the instructions under the “Possible Fix” column
to resolve the problem. Note: A good first step in troubleshooting a modem problem is
to verify the modem connection as explained in “Testing the Modem” earlier in this
chapter.
Possible Cause
Possible Fix
Modem Reports an Error When Dialing Out: If the modem is selected in the software but
gives an error when you try to dial out, refer to this section of the table.
The driver or CCL is corrupt or incorrect.
Make sure the correct driver is installed and the correct
CCL is selected and that they are not corrupted. If
necessary, reinstall the driver and/or CCL. If the
problem persists, reinstall the system software.
Computer Freezes When Modem Dials: If the computer locks up whenever the modem
is instructed to dial and the computer must be restarted, refer to this section of the
table.
Extensions are in conflict
or the OS is corrupted.
Enable only the Mac OS files in the Extensions Manager
and any modem drivers needed. If the problem persists,
reinstall the system software.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 6
Modem Not Connecting
This table should help you troubleshoot and fix a modem that is recognized and able to
dial out, but is having trouble connecting. The table is divided into different sections,
each with its own symptom and cure(s). Find your symptom and then follow the
instructions under the “Possible Fix” column to resolve the problem. Note: It is a
good idea to check the Activity Log (accessible via the Remote Access menu) to see if
there is an explanation for the failed connection attempt.
Possible Cause
Possible Fix
Error Launching a Browser: If the system returns an error message when you try to
launch an Internet browser, refer to this section of the table.
Browser software is not
installed correctly.
If more than one browser is installed, check to see if the
problem occurs with both browsers. If necessary,
reinstall the browser software. Note: Internet Explorer
4 and greater needs to be installed and not just drag
copied.
Dialup Software Problem: If the dialup software will not initiate a connection, refer to
this section of the table.
Dialup software is
installed incorrectly.
Make sure the software is fully installed and all required
extensions are enabled. If necessary, reinstall the dialup
software.
The phone line may have
too much noise.
If the user has a second line, try that one. The user
should contact their local phone company and request
their line be checked.
Can’t Select Features, or Access Sites, or Error Connecting to Online Site: If the Internet application is run but gives an error whenever it tries to connect to an online site
or the user has connected to the online service but cannot select any features, refer to
this section of the table.
TCP/IP control panel is
configured incorrectly.
Check to make sure the TCP/IP control panel is correctly
configured for the user's Internet service provider. If
the TCP/IP control panel is not configured correctly, it
will connect but won’t be able to access any sites.
The service may be down.
Sometimes online services use different servers for
dialup/authentication and for services. If one server is
down, users may be able to login but not access any
services. Contact the online service for help.
Can’t Connect to Remote Access Server or ISP: If the modem can’t connect to a particular remote access server or Internet service provider, refer to this section of the
table.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 7
This table should help you troubleshoot and fix a modem that is recognized and able to
dial out, but is having trouble connecting. The table is divided into different sections,
each with its own symptom and cure(s). Find your symptom and then follow the
instructions under the “Possible Fix” column to resolve the problem. Note: It is a
good idea to check the Activity Log (accessible via the Remote Access menu) to see if
there is an explanation for the failed connection attempt.
Possible Cause
Possible Fix
The phone number is
wrong.
Verify the phone number of the server you’re trying to
call. Dial the number using a regular telephone and
listen for the “whistle” of a modem. Make sure you’re
calling the type of server for which you’ve set up Remote
Access.
You don’t have access to the
server.
If you don’t have access to the server, you may get an
Authentication Failed message. Make sure you are a
registered user on the server or that the server is set up
for guest access. If trying to connect as a registered user,
verify that you’ve entered your name and password
correctly. Some servers require passwords that are
case-sensitive, meaning capitalization matters.
Pauses in dialing are
required.
You may need to create pauses while the number is being
dialed. Insert a comma between parts of the number
where a pause might be needed. Inserting a comma
lengthens the pause. For example, the following entries
cause Remote Access to dial “9” to get an outside line and
then pause before dialing the rest of the number:
9, 555-1234
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 8
Modem Dropping Connection
This table should help you troubleshoot and fix a modem that is dropping its connection
once it is established. The table is divided into different sections, each with its own
symptom and cure(s). Find your symptom and then follow the instructions under the
“Possible Fix” column to resolve the problem.
Possible Cause
Possible Fix
Modem Disconnects: If the user is disconnected after a few seconds/minutes of
connection, refer to this section of the table.
The phone line has noise
that is causing the modem’
to renegotiate until it
disconnects.
The phone line may be too noisy to handle the higher
modem speeds. Try connecting at a slower speed or use a
generic CCL file. (If you are familiar with the CCL script
language, you can edit the modem script to force a
connection at a lower speed.) If the problem continues,
contact the phone company to report the bad phone line.
The user has call waiting
on that phone line.
With call waiting active, an incoming call can interrupt
the connection. Disable call waiting using AT commands
placed in the init string of the dialup application. Usually
the string is *70.
There is a problem with
the server to which you
are connecting.
Servers sometimes develop problems that disconnect
users without explanation. Try calling back later or use
an alternate number if one is available.
The modem is loose or bad.
Reseat the modem. If the problem persists, replace the
modem.
User Disconnected After Period of Time: If the user leaves the computer for a while and
the modem is disconnected, refer to this section of the table.
Timed disconnect setting is
causing the modem to
disconnect.
Some services or software packages have a feature that
will disconnect the user after a set period of time. Either
increase this time setting or disable the feature if
possible. Contact the ISP or network administrator for
more information.
You are Left Waiting for a Callback: If you do not receive the required callback from the
server to which you are trying to connect, refer to this section of the table.
Your callback number is
incorrect.
Contact the network administrator to verify the callback
number you are using is correct and then try again.
You are using an incorrect
modem script.
If there is an attempt to callback but the connection fails,
verify you are using the correct modem script and then
try again.
Troubleshooting
Symptom/Cure Tables: System Problems After Startup - 5 9
Modem Performance Issues
This table should help you troubleshoot issues with the speed or response time of the
modem. The table is divided into different sections, each with its own symptom and
cure(s). Find your symptom and then follow the instructions under the “Possible Fix”
column to resolve the problem.
Possible Cause
Possible Fix
Slow Response: If the user has connected to the online service and is experiencing
very slow response to their actions or when accessing sites, refer to this section of the
table.
Too many people are using
the ISP's Internet
services.
When using an ISP, users need to remember that the ISP
only has a limited amount of bandwidth to the Internet. If
a large amount of people are dialing in, individual's
speeds will be affected.
The quality of the phone
line is limiting modem
performance.
Refer to “Modem Performance Issues” in the Basics
chapter for an overview of factors that can affect modem
performance.
System Freeze Occurs When Sleeping iMac Connected to Internet
System freeze occurs when a slot-load iMac (running Mac OS 8.6 or Mac OS 9) sleeps
with an active modem connection (PPP) to the Internet.
Possible Cause
Possible Fix
Software conflict affecting
slot-load iMacs running
Mac OS 8.6 or Mac OS 9.0.
Download and install Apple Audio Update 1.3 from http://
asu.info.apple.com/swupdates. System software versions
later than Mac OS 9.0 do not have this conflict.
K Service Source
Upgrades
iMac (Summer 2001)
Note: The parenthetical product description (Summer
2001) refers to the summer of the Northern
Hemisphere.
Upgrades
- 2
Memory
Install a memory module
that meets the following
specifications:
• JEDEC PC-100 DIMM
• 64, 128, 256, or 512
MB
• 168-pin
• 125 MHz (8 ns) or faster
Upgrades
- 3
Note: Place a soft towel or
cloth on the desk or surface.
Position the screen face
down on the cloth.
1. Using a flatblade
screwdriver or a coin,
turn the latch
counterclockwise to open
the rear access door.
2. Lower the access door.
Upgrades
- 4
3. Touch the EMI cover that
is visible inside the
recessed latch area
before touching any
components on the main
logic board. This
protects the computer
from damage caused by
electostatic discharge
.Important: If necessary,
remove any existing
memory module.
Upgrades
- 5
4. Push the ejector tabs on
the slots outward and
down so they are in the
open position.
Upgrades
- 6
5. Align the notches on the
memory module with the
small notches inside the
slot.
6. Push down on the DIMM
until it snaps into place.
The ejectors will
automatically close.
7. Close the rear access
door and test the
computer before
returning it to the
customer.
Upgrades
- 7
AirPort Card
Place a soft towel or cloth on
the desk or surface.
1. Position the screen face
down on the cloth.Use a
coin or flatblade
screwdriver to turn the
latch counterclockwise
on the access door.
2. Lower the access door to
open.
Upgrades
- 8
3. Touch the metal EMI
shield inside the
recessed latch area
before touching any
components on the main
logic board.
Upgrades
- 9
Guide Rails
Antenna
Protective
Antenna
Cap
4. Detach the antenna from
the left guide rail.
5. Remove the protective
antenna cap from the end
of the antenna and store
the cap in a safe place.
Upgrades
- 10
6. Slide the AirPort Card
into the adapter card.
Note: It is probably
easiest to attach the
metal ground clip over
the AirPort Card once
the card is installed into
the Adapter Card. This
photo shows the ground
clip already in place.
Upgrades
- 11
7. Connect the antenna by
plugging the antenna
wire into the small hole
in the end of the AirPort
Card.
Upgrades
AirPort
Adapter Card
Connector
- 12
AirPort Card
AirPort Adapter Ca
Guide Rails for
AirPort Card/
AirPort Adapter Card
8. Align the edges of the
AirPort Card with the
guides on the AirPort
Card slot. Insert the
AirPort Card into the
adapter Card connector.
9. Close the access door,
test the computer before
returning it to the
customer.
Upgrades
- 13
Connect an
External Monitor
The iMac (Early 2001)
computers have a VGA output
port for an external video
monitor. The external
monitor shows the same
information as the built-in
display, a mode sometimes
called hardware video
mirroring.
Upgrades
- 14
10. Place the computer face
down, on a soft, clean
cloth or ESD mat.
Upgrades
- 15
VGA
Output
Port
11. Plug the external
monitor cable into the
VGA output port on the
back of the computer.
VGA
Vented
Cover
12. Plug the monitor cable
into the monitor port on
the external monitor.
External
Monitor
Cable
13. Plug the power cord in
and press the Power
button on the computer
to turn it on.
14. Press the Power button
on the external monitor
to turn it on.
Upgrades
- 16
K Service Source
Adjustments
iMac (Summer 2001)
Note: The parenthetical product description (Summer
2001) refers to the summer of the Northern Hemisphere.
Adjustments
- 2
Important:
Adjustment
Information
The Adjustment procedures
for iMac (Summer 2001)
computer are identical to the
procedures for the slot
loading iMac (Summer
2000) and the iMac (Early
2001) computers.
These procedures can also be
found in the Knowledge Base.
Refer to article 95121:
iMac: Adjustment
Procedures.
Adjustments
Adjustment Tools - 3
Adjustment Tools
The following items are
needed to perform video
adjustments:
• Display Adjustment
Utility
• jumper adjustment tool
(922-4165)
• light meter Model R77
The utility can be found
online at: http://
service.info.apple.com.
Select Troubleshoot and
Repair/Reference/Safety.
Adjustments
Adjustment Tools - 4
Light Meter Setup
This topic covers setup for
light meter Model R77,
service part number 0760310.
Note: The adjustments were
optimized for light meter
Model R77. To obtain more
consistent color results, use
only the R77 light meter
when performing color
adjustments on the slot-load
iMac.
Adjustments
Adjustment Tools - 5
Model R77
Before you begin, remove
the 10X multiplier plate
from the lens.
Three scales are shown on
the light meter:
• 200-1000 fc
• 50-250 fc
• 10-50 fcT
Because display screen
luminance typically ranges
from 10 to 50 fc, take
readings from the bottom
scale only.
Adjustments
Adjustment Tools - 6
To measure a display
screen’s luminance,
1. Set the scale switch to
the bottom position (to
set up the 10-50 fc
scale).
2. Place the lens against the
middle of the screen and
read the bottom scale.
Note: When the light meter
is not in use, slide the scale
switch to its top position,
and store the meter in its
protective case.
Adjustments
Adjustment Tools - 7
If you suspect the light
meter is giving false
readings, verify the
readings with a known-good
light meter or photometer.
Also check the age of the R77
light meter by its four-digit
manufacturing date stamp
(such as 0398 for March
1998).
Caution: Dropping the
meter can permanently
damage its accuracy. A
shock-damaged meter might
read incorrectly or its
pointer may not drop to
zero.
Adjustments
Adjustment Tools - 8
Jumper Adjustment
Tool
The jumper adjustment tool
(922-4165) must be
installed to save cutoff and
white balance adjustments to
the factory space.
Adjustments
Adjustment Tools - 9
Installing the Jumper
±Warning:
This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review the Safety
information online at:
http://
service.info.apple.com.
Select Troubleshoot and
Repair, and click on Safety
under the Tools list.
1. Remove the bottom
housing and the top rear
housing to access the
video board.
Adjustments
Adjustment Tools - 1 0
2. With the power off,
remove the left ground
cable from the video
board.
Adjustments
Adjustment Tools - 1 1
3. Connect one end of the
jumper adjustment tool
(922-4165) to the
video board pin.
Note: The video board
pin is located
approximately one inch
below the ground pin and
is accessible through a
small hole in the video
board sheet metal
4. Connect the other end to
one of the ground pins.
5. Power on the iMac and
begin the adjustments.
Adjustments
Focus Adjustment - 1 2
Focus Adjustment
±Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review the Safety
information online at:
http://
service.info.apple.com.
Select Troubleshoot and
Repair, and click on Safety
under the Tools list.
1 Remove the bottom and
top rear housing to
access the focus
potentiometer on the
Adjustments
Focus Adjustment - 1 3
flyback transformer.
Note: Make sure the
jumper adjustment tool
is installed (see
previous procedure).
2. Power on the iMac.
3. Open the Display
Adjustment Utility and
select the Focus test
pattern from the Pattern
menu.
Adjustments
Focus Adjustment - 1 4
4. Adjust the focus control
on the flyback
transformer until the
focus test pattern
reaches the best frontof-screen performance.
Adjustments
Screen Voltage - 1 5
Screen Voltage
±Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review the Safety
information online at: http:/
/service.info.apple.com.
Select Troubleshoot and
Repair and click on Safety
under the Tools list.
Set the screen voltage:
• in a dimly lit room
• before performing the
cutoff and white balance
adjustments
Adjustments
Screen Voltage - 1 6
1. Remove the bottom
housing and the top rear
housing to access the
flyback transformer
that contains the screen
voltage potentiometer.
Adjustments
Screen Voltage - 1 7
2. With the power off,
remove the left ground
cable from the video
board.
Adjustments
Screen Voltage - 1 8
3. Connect the jumper
adjustment tool (9224165) to the video board
pin. Refer to the
“Jumper Adjustment
Tool” procedure
mentioned earlier in this
section.
Note: Without the
jumper installed, cutoff
and white balance
adjustments cannot be
saved. The jumper
enables writing the new
settings to the factory
space.
4. Power on the iMac.
Adjustments
Screen Voltage - 1 9
5. Open the Display
Adjustment Utility and
select the Color tab.
6. Set the Contrast to
maximum and the
Brightness to midrange.
7. Set the resolution to 800
x 600 in the Monitors
control panel.
Adjustments
Screen Voltage - 2 0
8. Select the Gray Bars test
pattern from the Pattern
menu.
Adjustments
Screen Voltage - 2 1
9. Looking at the Gray Bar
test pattern, turn the
screen voltage knob on
the flyback transformer
until:
• the first bar is black
• the second bar is
barely visible
• the third bar is a dark
gray
Note: The surrounding
raster should also be black.
10. When the requirements
in step 9 are met, the
screen voltage is set
correctly. Proceed to the
cutoff adjustment.
Adjustments
Cutoff Adjustment - 2 2
Cutoff Adjustment
±Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review the Safety
information online at http:/
/service.info.apple.com.
Select Troubleshoot and
Repair and click on Safety
under the Tools list.
Perform the cutoff
adjustment:
• whenever you replace the
CRT or the power/analog
/video board
Adjustments
Cutoff Adjustment - 2 3
• prior to the white balance
adjustment
• in a dimly lit room
Adjustments
Cutoff Adjustment - 2 4
Note: Set the Screen Voltage
if you haven’t done so
already. Refer to “Screen
Voltage ” mentioned earlier
in this section.
1. Remove the bottom
housing and the top rear
housing to access the
video board.
2. With the power off,
remove the left ground
cable from the video
board.
Adjustments
Cutoff Adjustment - 2 5
3. Connect the jumper
adjustment tool (see
graphic). Refer to
“Jumper Adjustment
Tool” mentioned earlier
in this section.
4. Power on the computer.
Make sure the monitor
has been on for at least
10 minutes before
making adjustments.
Adjustments
Cutoff Adjustment - 2 6
5. Open the Display
Adjustment Utility and
select the Color tab.
6. Set the drive and cutoff
controls to their
midpoint positions.
Note: The Revert and
Save buttons are
normally dimmed until a
slider bar is moved.
If you need to return to
the previous color
setting, either select
“Color Revert” from the
File menu or press the
<Command><R> keys.
Command-R should be
Adjustments
Cutoff Adjustment - 2 7
used if all the color
drive controls are set to
zero, and the screen is
completely black. The
Command-R function has
the same function as
Color Revert (from the
File menu) and the
Revert button on the
Color tab window.
Adjustments
Cutoff Adjustment - 2 8
7. Select the Gray Bars test
pattern from the Pattern
menu.
8. Look at the Gray Bar Test
pattern.
• The bars should have no
predominant color.
• The leftmost bar should
be black.
• The second bar from
the left should be
barely visible.
• The third bar should be
dark gray.
Adjustments
Cutoff Adjustment - 2 9
9. Select the Color tab
window.
10. Adjust the red, green,
and blue cutoff controls
until the second bar
(from the left) on the
Gray Bars test pattern is
barely visible and there
is no predominant color.
Adjustments
Cutoff Adjustment - 3 0
11. If there is a predominant
color in the three bars
on the left, continue
adjusting the color
controls accordingly
until there is no
predominant color.
When you are finished,
you should see shades
ranging from black and
white.
Note: Depending on the
monitor resolution
selected, the number of
gray bars displayed will
vary.
Adjustments
Cutoff Adjustment - 3 1
12. Click the Save button to
save your adjustments.
13. Proceed to the white
balance adjustment.
Adjustments
White Balance - 3 2
White Balance
Before you begin, make sure
the:
• cutoff is set correctly
• monitor has been on for at
least 10 minutes.
• jumper adjustment tool is
connected to the video
board (refer to “Jumper
Adjustment Tool”
mentioned earlier in this
section).
• room is dimly lit
Adjustments
White Balance - 3 3
1. Open the Display Service
Utility and select the
Gray Bars test pattern
from the Pattern menu.
Adjustments
White Balance - 3 4
2. Adjust the red, green,
and blue drive controls
until there is no
predominant color.
Adjustments
White Balance - 3 5
3. Select “White” from the
Pattern menu to display
the all-white test
pattern.
4. Hold the light meter
against the center of the
all-white screen.
The screen luminance
reading should be
33± 5fc (foot candles)
on the light meter Model
R77. If the luminance
readings are not within
spec, verify the meter is
functioning correctly.
Adjustments
White Balance - 3 6
5. Click the Save button to
save your settings.
6. Restart the computer and
reset the parameter RAM
(PRAM) to apply the
newly saved cutoff and
white balance
adjustments to the
Factory Setting.
To reset the PRAM, hold
down the
<Command><Option><P>
and <R> keys after
Restart is selected from
the Special menu.
Adjustments
White Balance - 3 7
Note: If you don’t
restart the computer,
the iMac will display the
last settings made on the
iMac.
7. Open the Monitors
control panel.
8. Select the Geometry icon.
Adjustments
White Balance - 3 8
9. Click the Factory
Settings button.
Adjustments
Geometry Adjustments - 3 9
Geometry
Adjustments
Before you begin, connect
the jumper adjustment tool
to the video board (refer to
the “Jumper Adjustment
Tool” mentioned earlier in
this section.
Note: Without the jumper
installed, geometry settings
cannot be saved. The jumper
enables writing the new
settings to the factory space.
Adjustments
Geometry Adjustments - 4 0
1. Open the Display
Adjustment Utility
2. Select the Geometry tab.
Adjustments
Geometry Adjustments - 4 1
3. Select a resolution for
adjustment from the
Resolution menu.
Note: Don’t use the
control strip or
Monitors control panel
to set the resolution.
Adjustments
Geometry Adjustments - 4 2
4. Adjust the geometry
settings by moving the
appropriate slider bar.
5. Click the Save button to
save the adjustments for
that resolution.
Note: Repeat steps 2-4
(for each resolution)
when adjusting width,
height, horizontal,
vertical, keystone, and
pincushion.
6. Restart the computer and
reset the parameter RAM
to save geometry
adjustments to the
Factory memory setting.
Adjustments
Geometry Adjustments - 4 3
7. To reset the PRAM, hold
down the
<Command><Option><P>
and <R> keys after
Restart is selected from
the Special menu.
Note: If you don’t
restart the computer,
the iMac will display the
previous user geometry
settings made on the
iMac.
8. Open the Monitors
control panel.
9. Select the Geometry icon.
Adjustments
Geometry Adjustments - 4 4
10. Click on the Factory
Settings button in the
Geometry window.
11. Close the Monitor
control panel.
Note: Rotation,
Parallelogram, Pincushion
Balance, and S Correction
adjustments are resolution
independent. Adjusting at one
resolution will apply to all
resolutions. Simply make
the changes and click the
Save button.
Adjustments
S Correction Adjustment - 4 5
S Correction
Adjustment
1. Open the Display
Adjustment Utility and
select “White Grid”
from the Pattern menu.
2. Check that all the
squares on the White
Grid test pattern appear
equal in size. If the
squares look fine, there
is no need for this
adjustment. If the
squares don’t look equal
in size, go on to the next
step.
Adjustments
S Correction Adjustment - 4 6
3. Open the Display
Adjustment Utility, and
select the Geometry tab.
4. If the squares need
adjusting, move the S
Correction slider bar.
5. Select the White Grid
test pattern again from
the Pattern menu and
check that all the
squares on the White
Grid test pattern appear
equal in size. If the
squares need further
adjusting, repeat steps
4 -5.
Adjustments
S Correction Adjustment - 4 7
6. When all the squares
look uniform on the S
Correction test pattern,
go back to the Geometry
tab window and click the
Save button.
7. Restart the computer and
reset the parameter RAM
(PRAM) to save these
adjustments to the
Factory Setting.
To reset the PRAM, hold
down the
<Command><Option><P>
and <R> keys after
Restart is selected from
the Special menu.
Adjustments
S Correction Adjustment - 4 8
Note: If you don’t
restart the computer,
the iMac will display the
last settings made on the
iMac.
8. Open the Monitors
control panel.
9. Select the Geometry icon.
Adjustments
S Correction Adjustment - 4 9
10. Click on the Factory
Settings button in the
Geometry window.
Note: Before returning
the iMac to the
customer, display the
focus test pattern again
and verify that the focus
is acceptable after all of
the adjustments have
been completed.
Service Source
Exploded View
iMac (Summer 2001)
Note: The parenthetical product description (Summer
2001) refers to the summer of the Northern Hemisphere.
Exploded View
2
iMac (Summer 2001) Exploded View
Screw Cap Top Right
922-4143
Screw CapTop Left
922-4142
Top Rear Housing
CRT
Assembly
(N. Hem.)
922-3877
(see Colored Service Parts Exploded View)
Bottom Housing
Microphone
922-4277
(see Colored Service Parts Exploded View)
Cover, VGA Out, Vented
922-4280
922-4317, Snow
Inner Bezel
922-4257
Front
Outer
Bezel*
Cover w/o VGA
922-4315
Screw
Cap
Left
Front
922-4140
RAM Access
Door
(see Colored Service Parts
Exploded View)
Power/Analog/Video Board
661-2465, Ver. 2 HH, w/switch at SW901
661-2466, Ver. 2 LG
Screw Cap
Right Front
922-4141
Clip, Metal, Wireless Antenna
922-4159
Left
Side Panel
922-4042
Wireless Antenna 922-4227
Speakers
Left & Right Kit
076-0820
Bracket Rear 922-4083
Thermal Pad, CPU, 922-4364
Headphone
Board 922-4225
Modem
661-2419
LED/Power Board, w/White LED
922-4524
Logic Boards
Down Converter Board
922-4518
661-2447 500 MHz, (education)
661-2425 500 MHz
661-2426 600 MHz
661-2548 700 MHz
CD/DVD Adapter Board
922-4027
I/O Panel
922-4393
CD-ROM, 24x 661-2346
CD-RW, 6X 661-2424
DVD-ROM, 6x, 661-2342
(CTO only)
HD/CD/DVD/CD-RW
Data Cable
922-4029
CD/DVD/CD-RW
Carrier 922-4041
Hard Drive
661-2327 20 GB
661-2423 40 GB
661-2521 60 GB
HD/CD/DVD/CD-RW Carrier
922-4040
Battery Lithium, 3.6 V
922-4028
AirPort
Adapter
Card
076-0804
SDRAM, DIMM
661-2145 64 MB, 168-pin
661-2146 128 MB, 168-pin
661-2398 128 MB, PC-133, 168-pin
661-2275 512 MB, 168-pin
AirPort Card (Optional)
661-2219
EMI Cover
922-3887
Right Side
Panel
922-4043
Exploded View
3
iMac (Summer 2001) Cable Locator
Exploded View
4
iMac (Summer 2001) Screw Matrix
Exploded View
5
iMac (Summer 2001) Colored Service Parts
Top Rear Housing
922-4245 Graphite, Ver. 2
922-4247 Indigo
922-4246 Snow
Front Outer Bezel
922-4251 Graphite
922-4253 Indigo
922-4609 Snow, Rev. 2
Speaker Kit (L and R)
076-0820
Bottom Housing
w/Flip Foot
922-4372 Graphite
922-4345 Indigo
922-4367 Snow
RAM Access Door
922-4281 Graphite
922-4282 Snow
922-4283 Indigo
Keyboard, Pro, USB
922-4320
Mouse, Pro
922-4230
Exploded View
6
Power/Analog/Video Boards
There are two part numbers for the power/analog/video board for the iMac (Summer
2001) computer because there are two vendors manufacturing the boards. The part
numbers are 661-2465, Ver. 2, HH and 661-2466, Ver. 2, LG. These boards must be
exchanged like-for-like.
The 661-2465 board has a switch at location SW901 that must be set for the type of CRT
tube in the computer. The switch settings are silk-screened on the board near SW901. If the
power/analog/video board or the CRT are replaced, make sure to set the switch to the
appropriate position (either to LG (for the LG CRT) or to CPT (for the CPT CRT)).
Exploded View
7
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