Apple macintosh portable Service Manual

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Service Source

Macintosh Portable

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Service Source

Basics

Macintosh Portable

Basics Overview - 1

Overview

This manual contains
complete repair procedures
for the Macintosh Portable
shown at left.

Figure: Macintosh Portable

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Service Source

Specifications

Macintosh Portable

Specifications Processor - 1

Processor

CPU

Addressing

Wait States

Motorola 68HC000, 16-bit CMOS microprocessor

15.6672 MHz

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

1 (static logic board)
10 (pseudostatic logic board)

Specifications Memory - 2

Memory

RAM

ROM

PRAM

VRAM

1 MB using thirty-two 32K by 8-bit static RAM chips; 100 ns

access time; addressing supports up to 9 MB
Expandable to 2 MB with optional 1 MB RAM expansion card
Expandable to 4 MB with optional 3 MB RAM expansion card

(backlit model)

256K using two 128K by 8-bit devices; 150 ns access time;

addressing supports up to 4 MB

128 bytes of system parameter memory

32K of static video display memory

Specifications Disk Storage - 3

Disk Storage

Floppy Drive

Hard Drive

Internal 1.4 MB floppy drive

Internal 40 MB hard drive (optional)

Specifications I/O Interfaces - 4

I/O Interfaces

Floppy Drive

SCSI

Apple Desktop Bus

Serial

Modem

DB-19 connector
Supports Macintosh 800K Disk Drive, Apple 3.5 Drive, Apple

SuperDrive, and Apple Hard Disk 20

1.5 MB/second transfer rate
Supports a maximum of eight devices

Low-speed serial interface
Supports optional low-power mouse

Two RS-422 serial ports; mini DIN-8 connectors

Phone jack for optional external modem

Specifications I/O Interfaces - 5

Power Adapter

Sound

Video

Power adapter port

Stereo sound-in port

DA-15 connector
Supports the connection of external video devices

Specifications I/O Devices - 6

I/O Devices

Keyboard

Low-Power ADB Mouse

Trackball

63 keys
N-key rollover
Apple Desktop Bus (ADB) interface
US, British, French Canadian, Japanese, German, Spanish,

French, Swedish, and Italian versions available

Low-power version of the ADB mouse
Opto-mechanical type
ADB interface

ADB interface

Specifications I/O Devices - 7

Numeric Keypad (Optional)

18 keys
ADB interface
US, Pacific, and European versions available

Specifications Sound and Video - 8

Sound and Video

Sound Generator

Video Display

Apple Sound Chip
One-or four-voice mono (one or two voices in stereo) with 4-bit

digital-to-analog conversion using a 22-kHz sampling rate
Filtered by two Sony sound chips

10-in. (diagonal) screen
Reflective, active-matrix, liquid crystal, flat-panel display
640 by 400 pixels, 75 dpi
.28 mm dot size; .33 mm dot pitch; 80% active area
Variable tilt
Contrast (nonbacklit display) and brightness (backlit display) is

software adjustable using the Control Panel.

Specifications Electrical - 9

Electrical

Main Battery

Backup Battery

Power Adapter

Input voltage:
Output voltage:

Sealed lead-acid

6.5 V
Up to 10 hours (fully charged battery); time depends on system

configuration and power management settings

9 V transistor

85–270 VAC (100/240 nominal), 48–62 Hz (50/60 nominal)

7.0–7.6 V (7.5 nominal), 5 mA–2.0 A (1.5 nominal)
US, Japanese, United Kingdom, Australian, and European versions

Specifications Electrical - 10

Battery Recharger (Optional)

Input voltage: 7.5 VAC
Battery recharger output voltage: 6.5 VDC

Specifications Physical - 11

Physical

Dimensions (Display Open)

Weight (With Battery)

Width: 15.25 in. (387.35 mm)
Height: 11.0 in. (279.4 mm)
Depth: 14.83 in. (365.25 mm)
Height at rear panel: 4.05 in. (102.87 mm)
Height at front panel: 2.10 in. (53.34 mm)

13.75 lb. (6.25 kg) without hard drive

15.75 lb. (7.16 kg) with hard drive

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Service Source

Troubleshooting

Macintosh Portable

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 Symptom Charts/Power - 2

Symptom Charts

Power

Screen is blank;
computer is not
responding

1 If computer is new, remove plastic sheet from between

battery and contacts.

2 Reset power manager.
3 Connect power adapter and restart computer in three or four

minutes.

4 Replace main battery.
5 Check keyboard cable connections.
6 Replace keyboard.
7 Replace keyboard cable.
8 Replace logic board. Retain customerÕs SIMMs.

Troubleshooting Symptom Charts/Power

(Continued)

- 3

After main battery is
removed, some
Control Panel settings
are different

Power adapter is
plugged in and
connected; battery DA
does not indicate
charger is connected

Power

1 Did you replace battery cover after removing main battery?

2 Replace backup battery.

1 Verify that charger is connected properly.
2 Replace main battery.
3 Replace power adapter.
4 Replace logic board. Retain customerÕs SIMMs.

(Continued)

If so, power interruption destroyed settings. Restore

contents of Control Panel.

Troubleshooting Symptom Charts/Power

(Continued)

- 4

Low-power warning
appears soon after
you start to use
computer

Battery does not
retain charge, even
when computer is not
in use

Power

1 Attach power adapter.
2 Make sure peripherals display low-power icon.
3 Reduce use of power-consuming devicesÑfor example, floppy

1 Upgrade to system software 6.0.5 or later.
2 Replace battery.
3 Replace keyboard.
4 Replace wire harness assembly.
5 Replace logic board.

(Continued)

drive, hard drive, modem, and speakerÑor connect power

adapter.

Troubleshooting Symptom Charts/Video - 5

Video

Some pixels never
come on; no pattern

Some pixels are
always black; no
pattern

Row of pixels is
always black

Row of pixels never
blackens

If display contains six or more voids, replace LCD display.
Maximum of five permanently OFF pixels (voids) is acceptable.

If any pixel is on constantly, replace LCD display.

1 Replace LCD display.
2 Replace display cable.
3 Replace logic board. Retain customerÕs SIMMs.

1 Replace LCD display.
2 Replace display cable.
3 Replace logic board. Retain customerÕs SIMMs.

Troubleshooting Symptom Charts/Video

(Continued)

- 6

Video

Display is blurred 1 Adjust angle of display.

2 Use Control Panel to adjust screen contrast.

Display is too dark 1 Move computer closer to direct light or move light source

2 Use Control Panel to adjust screen contrast.
3 Replace LCD display.
4 Replace logic board. Retain customerÕs SIMMs.

Display is too light 1 Adjust angle of display.

2 Use Control Panel to adjust screen contrast.
3 Replace LCD display.

(Continued)

closer to computer.

Troubleshooting Symptom Charts/Video

(Continued)

- 7

Backlight level cannot
be changed

Backlight does not
operate

Display is blank,
though computer
appears to operate
correctly

Video

Use version 1.3 of Portable CDEV.

1 Use version 1.3 of Portable CDEV.
2 Check inverter PCA connections.
3 Replace inverter PCA. Refer to ÒLCD Display (Backlit)Ó in

4 Replace LCD Display.
5 Replace logic board. Retain customerÕs SIMMs.

1 Check display cable connection.
2 Replace LCD display.
3 Replace display cable.
4 Replace logic board. Retain customerÕs SIMMs.

(Continued)

Take Apart.

Troubleshooting Symptom Charts/Floppy Drive - 8

Floppy Drive

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

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

1 Replace floppy disk.
2 Replace floppy drive.
3 Replace floppy drive cable.
4 Replace logic board. Retain customerÕs SIMMs.

1 Replace bad system disk with known good.
2 Replace floppy drive.
3 Replace floppy drive cable.
4 Replace logic board. Retain customerÕs SIMMs.

Troubleshooting Symptom Charts/Floppy Drive

(Continued)

- 9

Floppy Drive

Disk does not eject 1 Shut down computer, press and hold trackball or mouse

button, and switch on computer.

2 Eject disk manually by pushing opened paper clip into hole

near drive.

3 Replace floppy drive.
4 Replace floppy drive cable.
5 Replace logic board. Retain customerÕs SIMMs.

Disk initialization
fails

1 Verify that disk is Apple-certified.
2 Replace floppy disk.
3 Replace floppy drive.
4 Replace logic board. Retain customerÕs SIMMs.

(Continued)

Troubleshooting Symptom Charts/Hard Drive - 10

Hard Drive

Internal hard drive
does not operate

1 Switch on external SCSI devices connected to Portable.
2 Check hard drive cable connection.
3 Use HD SC Setup to see whether drive is visible. If it is,

reinitialize drive.

4 Replace hard drive.
5 Replace logic board. Retain customerÕs SIMMs.

Troubleshooting Symptom Charts/Peripherals - 11

Peripherals

After external SCSI
device is connected,
computer no longer
boots

Cursor does not move
when you use
trackball

1 Switch on external SCSI device before starting computer.
2 Verify that cable termination is correct.
3 Verify that no two SCSI devices have same device address.
4 Replace logic board. Retain customerÕs SIMMs.

1 Reset power manager.
2 Check cable connections between trackball and logic board.
3 Replace trackball cable.
4 Replace trackball.
5 Replace logic board. Retain customerÕs SIMMs.

Troubleshooting Symptom Charts/Peripherals

(Continued)

- 12

Cursor intermittently
does not move or
moves erratically

Cursor does not move
when you use mouse.

Cursor moves, but
clicking button has no
effect

Peripherals

1 Clean trackball ball and internal rollers.
2 Replace trackball.

1 Check mouse connection to ADB port.
2 Reset power manager.
3 Clean mouse ball and inside mouse.
4 Replace mouse.
5 Replace logic board. Retain customerÕs SIMMs.

1 If trackball button isnÕt working, replace trackball cable. If

mouse button doesnÕt work, replace mouse.

2 Replace trackball ball.
3 Replace logic board. Retain customerÕs SIMMs.

(Continued)

Troubleshooting Symptom Charts/Peripherals

(Continued)

- 13

No response to any
key on keyboard

Known-good
ImageWriter,
ImageWriter II, or LQ
doesnÕt print

Known-good
LaserWriter doesnÕt
print

Peripherals

1 Reset power manager by pressing reset and interrupt

switches simultaneously.

2 Check keyboard connection to logic board.
3 Replace keyboard.
4 Replace logic board. Retain customerÕs SIMMs.

1 Verify that System is 6.0.5 or later.
2 Verify Chooser settings.
3 Replace printer cable.
4 Replace logic board. Retain customerÕs SIMMs.

1 Verify that System is 6.0.5 or later.
2 Verify Chooser settings.
3 Replace printer. If new printer works, computer is OK.
4 Replace logic board. Retain customerÕs SIMMs.

(Continued)

Troubleshooting Symptom Charts/Peripherals

(Continued)

- 14

Device connected to
modem port doesnÕt
work

Serial devices are
unrecognized or
garbage is
transmitted and/or
received

Peripherals

1 Verify that External Modem is selected in the Portable CDEV.
2 Verify that System is 6.0.5 or later.
3 Replace logic board. Retain customerÕs SIMMs.

1 Use version 1.0 of Portable INIT.
2 Upgrade to system software 6.0.5 or later.

(Continued)