Apple PowerBook 550c Service Manual

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Service Source

Macintosh PowerBook 550c

This product is forJapan only.

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Service Source

Basics

Macintosh PowerBook 550c

Basics General Information - 1

General Information

The Macintosh PowerBook 550c features a built-in
trackpad, intelligent batteries, two battery bays, an
optional PCMCIA expansion module, a darker shade of
plastics, and a 10.4" display. The computer is available in
Japan only.

Basics Rear Panel - 2

Rear Panel

The illustration below shows the location of ports and
connectors on the rear panel of the Macintosh PowerBook
550c.

Basics PB Screw Matrix - 3

PB Screw Matrix

Nine different types of screws are used in the Macintosh
PowerBook 550c. All are Torx screws and require either a
T-8 or T-6 Torx screwdriver.

Note:

The legend for the screws follows on the next page.

Basics PB Screw Matrix - 4

Legend for Macintosh PowerBook 550c Screws

1 Feet

2 Hard drive, keyboard, bottom case (middle front),

display assembly, floppy drive, daughterboard EMI
shield (top edge), inside edge of top case, right side panel

3 Display bezel, display, clutch, DAA

4 Trackpad cable and actuator, daughterboard EMI shield

(sides), motherboard standoff

5 Rear panel

6 Hard drive bracket

7 Inverter board, interconnect board

8 Bottom case (front corners), left side panel

9 Floppy drive bracket

Basics PB Cable Matrix - 5

PB Cable Matrix

For a matrix of cables that work with specific models of the
PowerBook family of computers, refer to the PowerBook
Cable Matrix. (The Macintosh PowerBook 550c uses the
same cables as the Macintosh PowerBook 520/540 Series.)

Basics PCMCIA Module Handling - 6

PCMCIA Module Handling

The PCMCIA (Personal Computer Memory Card
International Association) expansion module is an option for
the Macintosh PowerBook 550c. The module inserts into the
computer’s second (left) battery bay and has two slots that
accept a variety of third-party PCMCIA cards.

There are three types of PCMCIA cards: Type I (3 mm),
Type II (5 mm), and Type III (10 mm). Type I and Type II
cards fit in either the upper or lower slot of the expansion
module. Type III cards fit in the lower slot and take up both
slots.

The following are guidelines for properly handling the
PCMCIA expansion module:

• Do not insert or remove the PCMCIA expansion module
while the computer is on or in Sleep mode. if you do, the

Basics PCMCIA Module Handling - 7

computer will shut down and all RAM contents will be
lost.

• Eject the PCMCIA module using the lever at the front of
the module; eject a PCMCIA card using the PCMCIA Eject
control panel or the PCMCIA Quick Eject module in the
computer’s Control Strip.

• Keep the protective cap that comes with the module and
place it back on the module when it is not in use.

• Do not open the module or insert anything other than a
PCMCIA card into the card slots.

• Keep the module in a safe place, away from small objects
that might fall into it.

• Before ejecting a PCMCIA card, make sure nothing is
blocking the card’s slot. To immediately reinsert the
card, pull it out an inch more and then push it back in.

• Use only cards that are compatible with the PCMCIA
expansion module. Refer to the compatibility
information that came with the card.

Basics Battery Handling - 8

Battery Handling

The Macintosh PowerBook 550c includes two nickel­metal-hydride (NiMH) batteries. Each battery provides
power for up to 3.5 hours of work time, depending on the
battery conservation features employed. A smart processor
included in each battery pack indicates the battery’s charge
status.

±

Warning:

undamaged, dead batteries to Apple for recycling—do not
discard dead batteries with other waste. If the battery is
damaged, do not return it to Apple. Dispose of damaged
batteries according to local ordinances. Review battery­handling and disposal instructions in Bulletins/Safety.

NiMH batteries contain toxic materials. Send

Basics Battery Handling - 9

The following are guidelines for properly handling the
Macintosh PowerBook 550c battery:

• Handle the battery carefully. Do not drop, puncture,
disassemble, mutilate, or incinerate it.

• Do not short-circuit the battery terminals.

• Do not leave a battery in the computer for longer than a
week without plugging in the power adapter.

• Do not leave the battery in hot locations (such as the
trunk of a car).

• Keep the battery in a cool, dark place; do not store it for
longer than 6 months without recharging.

• If you are using one battery: Completely discharge and
then recharge the battery once every 90 days.

• If you are using two batteries: Swap the left and right
batteries every month.

• Fully charge a replacement battery before using it;
Apple ships batteries in a partially charged state.

Basics Battery Verification - 10

Battery Verification

Negative
Probe

Positive
Probe

The Control Strip on the
Macintosh PowerBook 550c
desktop shows the battery
charge and the rate at which
the battery is being used.
Use a voltmeter to measure
the actual battery charge:

• Set the voltmeter to the
10 volts DC scale.

• Hold the positive probe of
the voltmeter to the
positive battery terminal
and the negative probe to
the negative terminal.

Basics Battery Verification - 11

• A fully charged battery
measures approximately

10.8 volts; a fully
discharged battery
measures 7.8 volts.

Note:

If a battery is stored
outside the computer for
extended periods, its voltage
may drop to 5.0.

Basics Adapter Verification - 12

Adapter Verification

Adapter

Plug

Negative
Probe

Positive
Probe

To verify the charge of the
AC adapter,

• Plug in the AC adapter to

a wall socket.

• Set a voltmeter to the 10

volts DC scale.

• Touch the positive volt-

meter probe to the inside
of the adapter plug and
touch the negative volt­meter probe to the
outside of the plug. If the
reading is not 16 volts,
replace the adapter.

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Service Source

Specifications

Macintosh PowerBook 550c

Specifications Processor - 1

Processor

CPU

Addressing

Motorola 68040 microprocessor
66/33 MHz

32-bit internal registers
32-bit address bus
32-bit data bus

Specifications Memory - 2

Memory

RAM

ROM

PRAM

VRAM

Clock/Calendar

4 MB RAM installed on the daughterboard
Expandable to 12 MB with 8 MB Apple RAM expansion card
Expandable to 36 MB with third-party RAM expansion card

2 MB

256 bytes of parameter memory

512K of static video display memory

CMOS custom chip with long-life lithium battery

Specifications Disk Storage - 3

Disk Storage

Floppy Drive

Hard Drive

15 mm high, internal, 1.4 MB Apple SuperDrive

2.5 in., 750 MB hard drive

Specifications I/O Interfaces - 4

I/O Interfaces

SCSI

Apple Desktop Bus

Serial

Sound

HDI-30 SCSI port with 1.5 MB/sec. transfer rate
Supports up to six external SCSI devices
Connect SCSI device to computer with HDI-30 SCSI system cable.

Apple Desktop Bus (ADB) port
200 mA maximum current draw for all ADB devices

RS-422 serial port; mini DIN-8 connector

Stereo sound-in port
Stereo sound-out headphone jack; standard 3.5 mm stereo

miniplugs

Specifications I/O Interfaces - 5

Video

Ethernet

Processor-Direct Slot

Power Adapter

Modem

Security

Micro DV-14 video-out port; 8 bit, 256 color video output
Supports most Macintosh, VGA, and SVGA monitors

High-speed Ethernet port; Apple AUI connector

90-pin processor-direct slot (PDS) for PDS devices or optional

Personal Computer Memory Card International Association
(PCMCIA) adapter/PCMCIA expansion module (allows use of
two Type II or one Type III PCMCIA-type card)

Power adapter port

Slot for optional internal modem

Slot for third-party security equipment

Specifications I/O Devices - 6

I/O Devices

Keyboard

Trackpad

Microphone

Built-in keyboard with 12 function keys
76 keys domestic, 77 keys ISO
Two-level tilt adjustment

Solid-state trackpad

Electret, omnidirectional
Output voltage of 4 mV, peak to peak

Specifications Sound and Video - 7

Sound and Video

Sound Generator

Video Display

Apple sound chip provides 16-bit sound capable of driving stereo

headphones or other stereo equipment through the sound jack

Built-in stereo speakers

10.4-in. diagonal screen
Backlit, active-matrix color display; 640 x 400 pixels at

thousands of colors; 640 x 480 pixels at 256 colors

Specifications Electrical - 8

Electrical

Main Battery

Power Adapter

Two nickel-metal-hydride (NiMH) batteries
Up to 3.5 hours of usage per battery before recharging
Recharge time: 2 hours in shut down or sleep mode, 4 hours while

computer is running

110–240 VAC line voltage
40 W, 50–60 Hz

Specifications Physical - 9

Physical

Dimensions

Height
Width
Depth

Weight

2.25 in. (5.7 cm)

11.5 in. (29.2 cm)

9.65 in. (24.5 cm)

7.3 lb. (3.3 kg)

Specifications Environmental - 10

Environmental

Operating Temperature

Storage Temperature

Relative Humidity

Operating Altitude

Storage Altitude

50–104°F (10–40°C)

-13 to 140°F (-25 to 60°C)

20–80% noncondensing

0–10,000 ft. (0–3048 m)

0–15,000 ft. (0–4572 m)

Specifications Other - 11

Other

Internal Modem

SCSI Adapter

PCMCIA Module

Sends and receives data at 19.2 bps; sends and receives faxes at

14.4 bps

Enables connection between PowerBook computer and desktop

Macintosh (PowerBook appears as a hard drive on the desktop)

Enables use of two Type I or II PCMCIA cards or one Type III card

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Service Source

Troubleshooting

Macintosh PowerBook 550c

Troubleshooting General - 1

General

The Symptom Charts included in this chapter will help you
diagnose specific symptoms related to your product. Because cures
are listed on the charts in the order of most likely solution, try
the first cure first. 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 cure.)

If you are not sure what the problem is, or if the Symptom Charts
do not resolve the problem, refer to the Flowchart for the product
family.

For additional assistance, contact Apple Technical Support.

Troubleshooting Power Manager Reset - 2

Power Manager Reset

Reset the power manager if

• The battery and power adapter are proven good, but the
computer will not power on.

• The computer will not reset after a system crash.

To reset the power manager in the Macintosh PowerBook 550c,

• Remove the AC adapter and the battery.

• Let the unit sit without power hooked up for 3–5 minutes.

• Simultaneously hold down the Control, Command, Option, and
Power On keys for 5–10 seconds.

• Reinstall the battery and, if necessary, reconnect the AC
adapter.

• Turn on the computer.

Troubleshooting AC Adapter Voltage Test - 3

AC Adapter Voltage Test

To test the AC adapter voltage,

• Use narrow test probes for the leads on your voltmeter

• Make all measurements with the negative or common lead
touching the outer shield of the connector (ground)

• Use the following table to identify the connector pin number,
signal name, and DC voltage present

Connector Pin Signal DC Voltage

1 VBATT 16.4–16.6V

2 VMAIN 16.4–16.6V

3 GND 0V

4 GND Sense 0V

Troubleshooting Symptom Charts/Startup - 4

Symptom Charts

Startup

RAM failure occurs
(eight-tone error
chord sounds after
startup chord)

Hardware failure
occurs (four-tone
error chord sounds
after startup chord)

1 Reseat RAM expansion card and check connection.
2 Replace RAM expansion card.
3 Replace daughterboard.
4 Replace motherboard.

1 Disconnect hard drive cable and restart computer. If startup

sequence is normal, reconnect cable and retest.
2 Replace hard drive.
3 Disconnect floppy drive cable and restart computer. If

startup sequence is normal, reconnect cable and retest.
4 Replace floppy drive.
5 Replace motherboard.

Troubleshooting Symptom Charts/Power - 5

Power

Screen is blank;
computer doesn’t
respond

1 Restart computer.
2 Connect power adapter and restart computer in 3–4 minutes.
3 Try known-good, charged main battery.
4 Check all interconnect board, daughterboard, and

motherboard connections.
5 Reset the power manager.
6 Replace keyboard.
7 Replace interconnect board.
8 Replace daughterboard.
9 Replace motherboard.

Troubleshooting Symptom Charts/Power

(Continued)

- 6

After you remove
main battery, some
Control Panel
settings are different

Power adapter is
plugged in, but
Control Strip doesn’t
indicate adapter is
connected

Power

1 Check cables.
2 Replace backup battery.
3 Replace interconnect board.
4 Replace daughterboard.
5 Replace motherboard.

1 Verify that power adapter is connected correctly.
2 Try known-good, charged main battery.
3 Try known-good power adapter.
4 Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Power

(Continued)

- 7

Low-power warning
appears

Computer runs when
plugged into wall
outlet but not on
battery power;
battery voltage is
within tolerance

Power

1 Recharge battery or attach power adapter.
2 Verify that peripherals are low-power.
3 Reduce use of floppy or hard drive, modem, sound, backlight,

4 Try known-good, charged main battery.
5 Try known-good power adapter.
6 Replace motherboard.

1 Reseat battery to make sure battery is mating with contacts

2 Replace motherboard.
3 Return computer to Apple.

(Continued)

or other power-consuming devices, or connect power

adapter.

on motherboard.

Troubleshooting Symptom Charts/Power

(Continued)

- 8

Computer won’t
power up

Power

1 Restart computer.
2 Connect power adapter and restart computer in 3–4 minutes.
3 Try known-good power adapter. Verify power adapter tip is

4 Try known-good, charged main battery.
5 Replace fuse on motherboard.
6 Replace motherboard.
7 Return computer to Apple.

(Continued)

not chipped or cracked.

Troubleshooting Symptom Charts/Video - 9

Video

Pixel never comes on
or is always on

Partial or full row of
pixels is always on or
never comes on

If more than five pixels do not come on or are always on, replace
display.

1 Check cables.
2 Replace interconnect board.
3 Replace motherboard.
4 Replace display.

Troubleshooting Symptom Charts/Video

(Continued)

- 10

Display is very light
or totally white

Display stopped
working or dimmed
but is fine now

Video

1 Adjust screen contrast and brightness settings.
2 Verify cable, inverter board, interconnect board,

3 Replace inverter board.
4 Replace interconnect board.
5 Replace interconnect-to-display cable.
6 Replace display.
7 Replace daughterboard.
8 Replace motherboard.

Let screen warm up for 30 minutes.

(Continued)

daughterboard, and motherboard connections.

Troubleshooting Symptom Charts/Video

(Continued)

- 11

Backlight doesn’t
operate

Video

1 Verify that backlight cable connection is secure.
2 Check cable, inverter board, interconnect board,

3 Verify that cables are not pinched or severed.
4 Replace inverter board.
5 Replace interconnect-to-inverter cable.
6 Replace interconnect board.
7 Replace interconnect-to-display cable.
8 Replace display.
9 Replace daughterboard.
10 Replace motherboard.

(Continued)

daughterboard, and motherboard connections.

Troubleshooting Symptom Charts/Video

(Continued)

- 12

No display, but
computer appears to
operate correctly

Video

1 Press any key to wake computer from system sleep.
2 Adjust screen contrast and brightness settings.
3 Verify cable, inverter board, trackpad, keyboard, inter-

4 Connect power adapter.
5 Replace inverter board.
6 Replace interconnect board.
7 Replace interconnect-to-display cable.
8 Replace display.
9 Reseat daughterboard.
10 Replace daughterboard.
11 Replace motherboard.

(Continued)

connect board, daughterboard, and motherboard connections.

Troubleshooting Symptom Charts/Floppy Drive - 13

Floppy Drive

Audio and video
present, but internal
floppy drive does not
operate

Disk ejects while
booting; display
shows Mac icon with
blinking X

1 Try known-good floppy disk.
2 Check floppy drive cable connection.
3 Replace floppy drive cable.
4 Replace floppy drive.
5 Replace motherboard.

1 Try known-good system disk.
2 Verify that trackpad and trackpad button are working.
3 Verify that keyboard is working.
4 Check floppy drive cable connection.
5 Replace floppy drive cable.
6 Replace floppy drive.
7 Replace motherboard.

Troubleshooting Symptom Charts/Floppy Drive

(Continued)

- 14

Floppy Drive

Disk does not eject 1 Switch off system and hold trackpad button down while you

switch system on.
2 Eject disk manually by carefully inserting opened paper clip

into hole near floppy drive slot.
3 If PowerBook serial number is between FC410 and FC414 or

between CD412 and CK414, replace floppy drive.
4 Check floppy drive cable connection.
5 Reinstall floppy drive brackets. (Refer to “Floppy Drive” in

Take Apart.)
6 Replace floppy drive cable.
7 Replace floppy drive.
8 Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Floppy Drive

(Continued)

- 15

Disk initialization
fails

Read/write/copy
error

Floppy Drive

1 Try known-good floppy disk.
2 Check floppy drive cable connection.
3 Replace floppy drive cable.
4 Replace floppy drive.

1 Try known-good floppy disk.
2 Check floppy drive cable connection.
3 Try application disk and data file on floppy disk.
4 Replace floppy drive cable.
5 Replace floppy drive.

(Continued)

Troubleshooting Symptom Charts/Hard Drive - 16

Hard Drive

Internal hard drive
does not operate

1 Make sure power adapter is connected.
2 Disconnect external SCSI devices.
3 Check hard drive cable connection.
4 Use HD SC Setup to reinitialize drive.
5 Replace hard drive cable.
6 Replace hard drive.
7 Replace motherboard.

Troubleshooting Symptom Charts/Peripheral - 17

Peripheral

After you connect
external SCSI device,
computer does not
boot

1 Switch on external SCSI device before starting computer.
2 Check cable connections.
3 Verify that SCSI chain is terminated correctly.
4 Verify that SCSI select switch setting on external device is

unique.
5 Verify operation of internal hard drive.
6 Try known-good external SCSI device.
7 Replace motherboard.

Troubleshooting Symptom Charts/Peripheral

(Continued)

- 18

Cursor does not move
when you are using
trackpad

Peripheral

1 Reset the power manager.
2 Check trackpad connections.
3 Check interconnect board, keyboard, and motherboard

connections.
4 Connect low-power mouse and try to move cursor. If cursor

moves, try using trackpad and keyboard. If trackpad does not

move cursor, replace trackpad. If keyboard does not move

cursor, replace keyboard.
5 Replace interconnect board.
6 Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Peripheral

(Continued)

- 19

Cursor intermittently
does not move or
moves erratically

Cursor does not move
when you are using
mouse

Peripheral

1 Reset the power manager.
2 Clean trackpad surface.
3 Check trackpad connections.
4 Replace trackpad.
5 Replace keyboard.
6 Replace interconnect board.
7 Replace motherboard.

1 Check mouse connection to ADB port.
2 Reset the power manager.
3 Clean mouse ball and inside mouse.
4 Replace mouse.
5 Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Peripheral

(Continued)

- 20

Cursor moves, but
clicking trackpad
button has no effect

No response to any
key on keyboard

Peripheral

1 Reset the power manager.
2 Check trackpad connections.
3 Check interconnect board, keyboard, and motherboard

connections.
4 Replace trackpad.
5 Replace keyboard.
6 Replace interconnect board.
7 Replace motherboard.

1 Verify that computer is on.
2 Reset the power manager.
3 Check keyboard and interconnect board connections.
4 Replace keyboard.
5 Replace interconnect board.
6 Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Peripheral

(Continued)

- 21

Known-good direct­connect printer does
not print

Peripheral

1 Verify that System is 7.1.1 or later.
2 Verify that Chooser and Control Panel settings are correct.
3 Check cables.
4 Replace printer cable.
5 Try known-good printer.
6 Replace daughterboard.
7 Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Peripheral

(Continued)

- 22

Known-good network
printer does not print

In disk mode,
computer does not
display SCSI icon
until host is booted,
or computer crashes
when host is shut
down

Peripheral

1 Verify that System is 7.1.1 or later.
2 Verify that Chooser and Control Panel settings are correct.
3 Check cables.
4 Replace printer cable.
5 Try known-good printer. If printer works, troubleshoot

network.
6 Replace daughterboard.
7 Replace motherboard.

Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Peripheral

(Continued)

- 23

Device connected to
external modem port
doesn’t work

I/O devices are
unrecognized or
garbage is
transmitted or
received

Peripheral

1 Verify that External Modem is selected in CDEV.
2 Verify that System is 7.1.1 or later.
3 Check cables.
4 Test device with known-good computer.
5 Replace daughterboard.
6 Replace motherboard.

1 Verify that System is 7.1.1 or later.
2 Check cables.
3 Verify that SCSI device is correctly terminated.
4 Verify that SCSI select switch setting on external device is

unique.
5 Test device with known-good computer.
6 Replace daughterboard.
7 Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Internal Modem - 24

Internal Modem

Internal modem
options do not appear
in CDEV

Modem does not
respond properly to
AT command set
instructions

1 Verify that System is 7.1.1 or later.
2 Reseat modem card.
3 Replace modem card.
4 Replace motherboard.

1 Verify that baud rate and data format settings of

communications application are compatible with internal

modem and remote modem.
2 Check phone cord connection and operation.
3 Verify that System is 7.1.1 or later.
4 Reseat modem card.
5 Replace modem card.

Troubleshooting Symptom Charts/Internal Modem

(Continued)

- 25

Strange mix of
characters appears
on screen

Modem interferes
with system sound

Internal Modem

1 Verify that baud rate and data format settings of

communications application are compatible with internal

modem and remote modem.
2 Check phone cord connection and operation.
3 Verify that System is 7.1.1 or later.
4 Reseat modem card.
5 Replace modem card.
6 Replace daughterboard.
7 Replace motherboard.

1 Reseat modem card.
2 Replace modem card.
3 Replace interconnect board.
4 Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Internal Modem

(Continued)

- 26

Modem does not
respond to incoming
call

Modem has no sound
output

Internal Modem

1 If computer is in sleep mode, verify that Wake On Ring

option in CDEV is selected.
2 Check phone cord connection and operation.
3 Replace modem card.
4 Replace motherboard.

1 Verify that Control Panel volume setting is above 0.
2 Replace modem card.
3 Replace interconnect board.
4 Replace motherboard.

(Continued)

Troubleshooting Symptom Charts/Internal Modem

(Continued)

- 27

Modem connects but
does not communicate
with remote modem

Internal Modem

1 Verify that remote modem needs error correction (error

correction is internal modem default).
2 If remote modem does not need error correction, type AT

&Q0 to disable error correction.

(Continued)

Troubleshooting Symptom Charts/Internal Modem

(Continued)

- 28

You are using System

7.5 and two messages
appear: “This
Macintosh may not
have been shut down
properly” and
“Incoming fax cannot
be received because
internal modem could
not be identified...”
Following the
messages, the system
“hangs.”

Internal Modem

1 Restart while holding down the Space bar. (This procedure

will open Extensions Manager.)

• Disable the PowerPort 500 control panel by removing the
check mark.

• Close the Extensions Manager window to complete startup.

• Open the General Controls control panel and turn off the
shutdown warning.

• Open the Extensions Manager control panel and turn on the
PowerPort 500 control panel.

• Restart.

2 Restart with extensions off and remove the GlobalFax files,

GlobalFax Personal folders, and PowerPort 500 from the
System folder.

• Reinstall the Global Village software.

• Move the GlobalFax addresses into a new folder.

(Continued)

Troubleshooting Symptom Charts/PCMCIA Module - 29

PCMCIA Module

PCMCIA card won’t
eject

PCMCIA card is
inserted but doesn’t
appear on desktop

1 Make sure PCMCIA slot is not blocked.
2 Insert straightened paper clip into hole next to slot.

If “defective card” or “unrecognizable card” appears in place of
card name in PCMCIA Eject control panel, card is damaged or
computer does not have software required to support it. Eject
card.

Troubleshooting Symptom Charts/Miscellaneous - 30

Miscellaneous

Screen goes blank and
computer shuts down
every few minutes

Application seems to
run slower after a few
seconds

Hard drive is slow to
respond, or screen
goes blank too often

Computer is going into system sleep to conserve battery power.
Adjust sleep delays in Control Panel or connect power adapter.

Computer is switching to system rest. If system rest is
interfering with operation of application, connect power adapter.

Adjust sleep delays in Control Panel or connect power adapter.

Troubleshooting Symptom Charts/Miscellaneous

(Continued)

- 31

No sound from
speaker

PowerBook clicks
when closed

Miscellaneous

1 Verify that volume setting in Control Panel is above 0.
2 Verify that no external speaker is plugged in.
3 Check connections of speaker to interconnect board and

interconnect board to motherboard.
4 Replace interconnect board.
5 Replace motherboard.

Reinstall center base cover, making sure screw nearest SCSI port
is installed first. (See Take Apart.)

(Continued)

K

Service Source

T ak e Apart

Macintosh PowerBook 550c

Take Apart Battery/PCMCIA Module - 1

Battery/PCMCIA Module

Before you begin, discon­nect the power adapter.

Note:

This procedure covers

removal of the main battery,

Second Battery/
PCMCIA Module

second battery or PCMCIA
expansion module, and
battery contact cover.

Main Battery

Important:

the battery, use the
Macintosh Shut Down
command. Otherwise, all
RAM contents will be lost.

Before removing

Take Apart Battery/PCMCIA Module - 2

Release
Button

Caution:

The Macintosh
PowerBook 550c contains
devices that are very
susceptible to ESD damage.
To prevent damage, wear a
grounding wriststrap.
Review the ESD precautions
in Bulletins/Safety.

1 Slide the release button

toward you and pull out
the main battery on the
right side of the
computer.

2 Repeat the procedure

for the second battery, if
installed, on the left
side of the computer.

Take Apart Battery/PCMCIA Module - 3

3

Note:

The battery bezel
includes a separate latch
and latch spring.
Remove the bezel

Battery

Bezel

carefully so these parts
do not fall out.

If you are replacing the
battery bezel, pry up
both ends of the bezel and
lift it off the main
battery.

Latch/
Spring

Replacement Note:

Make
sure the battery bezel
latch spring is com­pressed against the end
of the battery before
replacing the bezel.

Take Apart Battery/PCMCIA Module - 4

4 If you are replacing the

battery contact cover,
press in on the sides of

Battery Contact Cover

the cover and slide it off
the main battery.

Take Apart Battery/PCMCIA Module - 5

5

Note:

Complete the
following step if a
PCMCIA expansion
module is installed in the
computer.

Using the tip of your
finger, rotate the lever
at the front of the
PCMCIA module toward
you.

6

Note:

You may have to
use some force when
pulling the module out
of the computer.

Lever

Holding onto the lever,
pull the PCMCIA module
out of the computer.

Take Apart Keyboard - 6

Keyboard

Before you begin, remove
the battery/PCMCIA module.

Keyboard

Take Apart Keyboard - 7

1 Using a T-8 torx driver,

remove the middle two
bottom housing screws.

Take Apart Keyboard - 8

2 Using a small flat-blade

screwdriver, lift the
front of the keyboard and
pull it forward slightly.

3 Rotate the keyboard so

that it is perpendicular
to the top cover.

Keyboard

Take Apart Keyboard - 9

4 Release the locking tabs

on the two keyboard

Locking
Tabs

cable connectors and
disconnect the cables
from the motherboard.

5 Lift off the keyboard.

Take Apart Hard Drive - 10

Hard Drive

Before you begin, remove
the following:

• Battery/PCMCIA module

• Keyboard

Hard Drive

Take Apart Hard Drive - 11

1 Using a T-8 torx driver,

remove the hard drive
mounting screw.

Take Apart Hard Drive - 12

2 Using a small flat-blade

screwdriver, pry up the
front of the hard drive
and slide it forward 1/2

Hard Drive

inch.

3

Note:

Use a rocking
motion to disconnect the

Hard

Drive

Cable

hard drive cable from
the hard drive.

Lift the drive partway
out of the unit and
disconnect the hard drive
cable.

4 Remove the hard drive.

Take Apart Hard Drive - 13

5 If you are replacing the

hard drive, remove the
four screws and remove
the hard drive bracket
and insulator.

Bracket

Insulator

Replacement Note:

Reinstall the hard drive
bracket and insulator on
the replacement hard
drive.

Take Apart Clutch Covers - 14

Clutch Covers

Before you begin, remove
the battery/PCMCIA module.

Clutch Cover

Clutch Cover

Take Apart Clutch Covers - 15

1 Open the unit and rotate

the display assembly as
far back as it will go.

2 Using a flat-blade

screwdriver and your
fingers, press in on
both sides of the wide end
of the right clutch cover
and release the two
front latches.

3 Rotate the clutch cover

up, release the third
latch, and remove the
cover.

Latch

4 Repeat for the left clutch

cover.

Take Apart Clutch Covers - 16

Replacement Caution

careful not to pinch or rip
the display cable when you
replace the right clutch
cover.

: Be

Take Apart Display Access Cover - 17

Display Access Cover

Before you begin, remove
the battery/PCMCIA module.

Display Access

Cover

Take Apart Display Access Cover - 18

1 Open the unit and rotate

the display assembly as
far back as it will go.

2 Using a small flat-blade

screwdriver, pry up the
display access cover at
the three slots in the
front of the cover.

3 Remove the display

access cover.

Take Apart Display Assembly - 19

Display Assembly

Before you begin, remove
the following:

• Battery/PCMCIA module

Display Assembly

• Clutch covers

• Display access cover

Take Apart Display Assembly - 20

Interconnect-to-Logic

Board Cable

Caution:

Support the
display assembly from
beneath before removing it.

1 Open the unit and rotate

the display assembly as
far back as it will go.

2 Disconnect the

interconnect-to-logic­board cable.

3 Using a T-8 torx driver,

remove the two display
mounting screws.

4 Slide the display

assembly to the left so
that the right clutch
clears the loop of the

Take Apart Display Assembly - 21

interconnect-to-logic­board cable.

5 Remove the display

assembly.

Take Apart Center Base Cover - 22

Center Base Cover

Before you begin, remove
the following:

• Battery/PCMCIA module

• Keyboard

Center Base Cover

Take Apart Center Base Cover - 23

1 Using a T-8 torx driver,

remove the two rear
panel screws.

Replacement Caution:

When replacing the rear
panel screws, be sure to
install the right screw
first (the screw nearest
the SCSI port).

Take Apart Center Base Cover - 24

2 Pull the center base

cover forward slightly
and slide it 1/2 inch to
the right to release the
two screw carriers.

3 Remove the center base

Screw Carrier

cover.

Take Apart Floppy Drive - 25

Floppy Drive

Before you begin, remove
the following:

• Battery/PCMCIA module

• Keyboard

• Center base cover

Floppy Drive

Take Apart Floppy Drive - 26

1 Using a T-8 torx driver,

remove the two floppy
drive screws.

Take Apart Floppy Drive - 27

2 Using a small flat-blade

screwdriver, pry up the
cable end of the floppy
drive and slide the drive
1/2 inch to the left.

3 Slide the drive forward

slightly and lift it
partway out of the unit.

4 Disconnect the floppy

drive cable from the
motherboard and
remove the drive.

Floppy Drive Cable

Take Apart Floppy Drive - 28

Floppy Drive Cable

Replacement Caution:

Before disconnecting the
floppy drive cable from
the drive, note the cable
folds and the correct
orientation of the cable
connection. Because the
cable connector is not
keyed, the floppy drive
cable could be reinserted
upside down.

Replacement Caution:

When you reinstall the
floppy drive, make sure
the floppy drive cable
folds on top of the drive,
not below it.

Take Apart Floppy Drive - 29

5 If you are replacing the

floppy drive or floppy
drive cable, release the
locking tabs and
disconnect the cable
from the drive.

Locking Tab

Floppy Drive Cable

Take Apart Floppy Drive - 30

6 If you are replacing the

floppy drive, remove the
two right bracket screws
and remove the right
bracket.

7 Remove the two left

bracket screws and
remove the left bracket.

Take Apart Floppy Drive - 31

Right Bracket

Replacement Note:

Reinstall the floppy
drive brackets and
floppy drive cable on
the replacement floppy
drive. Use the following
procedure for the
brackets:

• Start the screws in
the right bracket.

• Push the front of the
bracket toward the
top of the floppy drive.

• Hold the bracket in
this position and
retighten the screws.

• Repeat for the left
bracket.

Take Apart Floppy Drive - 32

Replacement Caution:

If the brackets are not
pushed toward the top of
the floppy drive, the
floppy disk may not eject
properly.

Take Apart Daughterboard EMI Shield - 33

Daughterboard EMI Shield

Before you begin, remove
the following:

• Battery/PCMCIA module

• Keyboard

• Center base cover

Daughterboard
EMI Shield

Take Apart Daughterboard EMI Shield - 34

1 Remove the three

mounting screws.

2 Using a small flat-blade

screwdriver, pry up
and remove the
daughterboard EMI
shield.

Daughterboard

EMI Shield

Replacement Caution:

Make
sure all the tabs on the sides
of the shield fit inside the
daughterboard guide.

Take Apart Daughterboard - 35

Daughterboard

Before you begin, remove
the following:

• Battery/PCMCIA module

• Keyboard

• Center base cover

• Daughterboard EMI shield

Daughterboard

• RAM card (if installed)

• Modem card (if installed)

Take Apart Daughterboard - 36

Note:

To remove the
daughterboard, you will need
to adapt an IC extractor so
that it has a wide grip.

1 Grasp an IC extractor by

the legs and pull
outward.

Take Apart Daughterboard - 37

2 Remove the plastic

retainer bar.

3

Note:

The daughterboard
is connected to the
motherboard below the
RAM card connector.

Daughterboard

RAM Expansion Connector

Daughterboard Connector

Notch

Caution:

You may have
to use some force to
disconnect the daughter­board. Use an IC
extractor, as illustrated.
Do not pry up the board
with a screwdriver.

Place the legs of the IC
extractor in the notches
at the end of the daugh­terboard and pull up.

Take Apart Top Case - 38

Top Case

Before you begin, remove
the following:

Top Case

• Battery/PCMCIA module

• Clutch covers

• Display access cover

• Display assembly

• Keyboard

• Hard drive

• Center base cover

• Floppy drive

Take Apart Top Case - 39

1 Rotate the feet to the up

position.

2 Using a T-8 torx driver,

Small Screw

Small Screw

remove the screw located
under each foot.

3 Remove the four screws

at the front edge of the
bottom case.

Take Apart Top Case - 40

4 Remove the remaining

screw on the inside top
edge of the case.