Toshiba A20-S259 - Satellite - Pentium 4 2.66 GHz User manual

Toshiba Personal Computer
Satellite A20 Series
Maintenance Manual
TOSHIBA CORPORATION
File Number 960-444

ii Satellite A20 Maintenance Manual (960-444)
Copyright
© 2003 by Toshiba Corporation. All rights reserved. Under the copyright laws, this manual cannot
be reproduced in any form without the prior written permission of Toshiba. No patent liability is
assumed with respect to the use of the information contained herein.
Toshiba Personal Computer Satellite A20 Series Maintenance Manual
First edition May 2003
Disclaimer
This manual has been validated and reviewed for accuracy. The instructions and descriptions it
contains are accurate for the TOSHIBA A20 Series Portable Personal Computer at the time of this
manual's production. However, succeeding computers and manuals are subject to change without
notice. TOSHIBA assumes no liability for damages incurred directly or indirectly from errors,
omissions or discrepancies between the computer and the manual.
Trademarks
Intel, Intel SpeedStep and Pentium are trademarks or registered trademarks of Intel Corporation or
its subsidiaries in the United States and other countries/regions.
Windows and Microsoft are registered trademarks of Microsoft Corporation.
Photo CD is a trademark of Eastman Kodak.
Bluetooth is a trademark owned by its proprietor and used by TOSHIBA under license.

Satellite A20 Maintenance Manual (960-444)iii
Preface
This maintenance manual describes how to perform hardware service maintenance for the Toshiba
Personal Computer Satellite A20 Series, referred to as A20 Series in this manual.
The procedures described in this manual are intended to help service technicians isolate faulty Field
Replaceable Units (FRUs) and replace them in the field.
SAFETY PRECAUTIONS
Four types of messages are used in this manual to bring important information to your attention.
Each of these messages will be italicized and identified as shown below.
DANGER: “Danger” indicates the existence of a hazard that could result in death or
serious bodily injury, if the safety instruction is not observed.
WARNING: “Warning” indicates the existence of a hazard that could result in bodily
injury, if the safety instruction is not observed.
CAUTION: “Caution” indicates the existence of a hazard that could result in property
damage, if the safety instruction is not observed.
NOTE: “Note” contains general information that relates to your safe maintenance
service.
Improper repair of the computer may result in safety hazards. Toshiba requires service technicians
and authorized dealers or service providers to ensure the following safety precautions are adhered
to strictly.
qBe sure to fasten screws securely with the right screwdriver. If a screw is not fully fastened,
it could come loose, creating a danger of a short circuit, which could cause overheating,
smoke or fire.
qIf you replace the battery pack or RTC battery, be sure to use only the same model battery
or an equivalent battery recommended by Toshiba. Installation of the wrong battery can
cause the battery to explode.

iv Satellite A20 Maintenance Manual (960-444)
The manual is divided into the following parts:
Chapter 1 Hardware Overview describes the Satellite A20 Series system unit and
each FRU.
Chapter 2 Troubleshooting Procedures explains how to diagnose and resolve FRU
problems.
Chapter 3 Test and Diagnostics describes how to perform test and diagnostic
operations for maintenance service.
Chapter 4 Replacement Procedures describes the removal and replacement of the
FRUs.
Appendices The appendices describe the following:
qHandling the LCD module
qBoard layout
qPin assignments
qKeyboard scan/character codes
qKey layout
qWiring diagrams
qBIOS Rewrite Procedures
qReliability

Satellite A20 Maintenance Manual (960-444)v
Conventions
This manual uses the following formats to describe, identify, and highlight terms and operating
procedures.
Acronyms
On the first appearance and whenever necessary for clarification acronyms are enclosed in
parentheses following their definition. For example:
Read Only Memory (ROM)
Keys
Keys are used in the text to describe many operations. The key top symbol as it appears on the
keyboard is printed in boldface type.
Key operation
Some operations require you to simultaneously use two or more keys. We identify such operations
by the key top symbols separated by a plus (+) sign. For example, Ctrl + Pause (Break) means
you must hold down Ctrl and at the same time press Pause (Break). If three keys are used, hold
down the first two and at the same time press the third.
User input
Text that you are instructed to type in is shown in the boldface type below:
DISKCOPY A: B:
The display
Text generated by the computer that appears on its display is presented in the type face below:
Format complete
System transferred

vi Satellite A20 Maintenance Manual (960-444)

Satellite A20 Maintenance Manual (960-444)vii
Table of Contents
Chapter 1 Hardware Overview
1.1 Features.......................................................................................................................1-1
1.2 System Unit Block Diagram..........................................................................................1-7
1.3 2.5-inch Hard Disk Drive ...........................................................................................1-14
1.4 CD-RW/DVD Drive..................................................................................................1-16
1.5 DVD-R/-RW Drive ...................................................................................................1-19
1.6 DVD Multi Drive .......................................................................................................1-20
1.7 Keyboard..................................................................................................................1-23
1.8 TFT Color Display.....................................................................................................1-24
1.9 Power Supply............................................................................................................1-26
1.10 Batteries ....................................................................................................................1-28
Chapter 2 Troubleshooting Procedures
2.1 Troubleshooting ...........................................................................................................2-1
2.2 Troubleshooting Flowchart...........................................................................................2-3
2.3 Power Supply Troubleshooting.....................................................................................2-7
2.4 System Board Troubleshooting...................................................................................2-19
2.5 FDD Troubleshooting.................................................................................................2-33
2.6 HDD Troubleshooting................................................................................................2-36
2.7 Keyboard Troubleshooting.........................................................................................2-41
2.8 Display Troubleshooting.............................................................................................2-44
2.9 CD-RW/DVD, DVD-ROM, DVD-R/-RW
and DVD Multi Drive Troubleshooting........................................................................2-46
2.10 Modem Troubleshooting ............................................................................................2-48
2.11 LAN Troubleshooting ................................................................................................2-50
2.12 Wireless LAN Troubleshooting ..................................................................................2-52
2.13 Sound Troubleshooting...............................................................................................2-56

viii Satellite A20 Maintenance Manual (960-444)
2.14 SD Card Troubleshooting...........................................................................................2-59
Chapter 3 Tests and Diagnostics
3.1 The Diagnostic Test......................................................................................................3-1
3.2 Executing the Diagnostic Test .......................................................................................3-3
3.3 Subtest Names.............................................................................................................3-7
3.4 System Test.................................................................................................................3-9
3.5 Memory Test.............................................................................................................3-12
3.6 Keyboard Test...........................................................................................................3-14
3.7 Display Test...............................................................................................................3-18
3.8 Floppy Disk Test .......................................................................................................3-22
3.9 Printer Test................................................................................................................3-24
3.10 Async Test.................................................................................................................3-26
3.11 Hard Disk Test ..........................................................................................................3-27
3.12 Real Timer Test..........................................................................................................3-30
3.13 NDP Test..................................................................................................................3-32
3.14 Expansion Test...........................................................................................................3-34
3.15 CD-ROM/DVD-ROM Test ......................................................................................3-36
3.16 Wireless LAN Test (Agere) ......................................................................................3-37
3.17 Wireless LAN Test (Atheros)....................................................................................3-42
3.18 Sound/LAN/Modem Test ..........................................................................................3-45
3.19 Error Code and Error Status Names...........................................................................3-51
3.20 Hard Disk Test Detail Status ......................................................................................3-54
3.21 Head Cleaning ...........................................................................................................3-56
3.22 Log Utilities................................................................................................................3-57
3.23 Running Test..............................................................................................................3-59
3.24 Floppy Disk Drive Utilities..........................................................................................3-61
3.25 System Configuration.................................................................................................3-66
3.26 SETUP......................................................................................................................3-68

Satellite A20 Maintenance Manual (960-444)ix
Chapter 4 Replacement Procedures
4.1 General........................................................................................................................4-1
4.2 Battery Pack................................................................................................................4-9
4.3 Optional PC Card......................................................................................................4-11
4.4 Optional SD Card......................................................................................................4-13
4.5 HDD .........................................................................................................................4-14
4.6 Modem Daughter Card..............................................................................................4-18
4.7 Slim Select Bay Module .............................................................................................4-20
4.8 Cooling Fan...............................................................................................................4-24
4.9 CPU..........................................................................................................................4-27
4.10 Keyboard..................................................................................................................4-32
4.11 Memory Module........................................................................................................4-36
4.12 Wireless LAN Card...................................................................................................4-38
4.13 Bluetooth...................................................................................................................4-41
4.14 Switch Board.............................................................................................................4-43
4.15 Top Cover with Display Assembly..............................................................................4-45
4.16 Touch Pad.................................................................................................................4-48
4.17 Front Membrane ASSY.............................................................................................4-50
4.18 USB Board................................................................................................................4-52
4.19 Sound Board .............................................................................................................4-54
4.20 RTC Battery..............................................................................................................4-56
4.21 DC-IN Jack ..............................................................................................................4-58
4.22 System Board............................................................................................................4-59
4.23 Sub Fan.....................................................................................................................4-61
4.24 PC Card Slot.............................................................................................................4-63
4.25 Speakers ...................................................................................................................4-65
4.26 Touch Pad Switch......................................................................................................4-67
4.27 Display Mask.............................................................................................................4-68
4.28 FL Inverter ................................................................................................................4-70
4.29 LCD Module .............................................................................................................4-72

xSatellite A20 Maintenance Manual (960-444)
4.30 Wireless LAN Antenna/Blutooth Antenna/Display Cover............................................4-76
4.31 Fluorescent Lamp ......................................................................................................4-85
Appendices
Appendix A Handling the LCD Module .............................................................................. A-1
Appendix B Board Layout...................................................................................................B-1
Appendix C Pin Assignments.............................................................................................. C-1
Appendix D Keyboard Scan/Character Codes.................................................................... D-1
Appendix E Key Layout......................................................................................................E-1
Appendix F Wiring Diagram................................................................................................F-1
Appendix G BIOS Rewrite Procedures............................................................................... G-1
Appendix H EC/KBC Rewrite Procedures ......................................................................... H-1
Appendix I Reliability..........................................................................................................I-1