Toshiba Libretto 100CT User manual

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1Toshiba Personal Computer
Copyright
©1998 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 Libretto 100CT Maintenance Manual
First edition February 1998
Disclaimer
The information contained in this manual is subject to change without notice.
Toshiba Corporation and Toshiba America Information Systems, Inc., assume no liability for damages
incurred directly or indirectly from errors, omissions, or discrepancies in connection with the furnishing,
performance, or use of this material.
Trademarks
IBM is a registered trademark, and PC/AT, PS/2 and OS/2 are trademarks of IBM Corporation.
MS-DOS and Windows are registered trademarks of Microsoft Corporation.
Intel and Pentium are registered trademarks, and MMX is a trademark of Intel Corporation.
Lotus is a registered trademark of Lotus Development Corporation.
Novell and NetWare are registered trademarks of Novell, Inc.
UNIX is a registered trademark of X/Open Company Ltd.
Sound Blaster and Pro are trademarks of Creative Technology Ltd.
Centronics is a registered trademark of Centronics Data Computer Corporation.
All other properties are trademarks or registered trademarks of their respective holders.

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Preface
This maintenance manual describes how to perform hardware service maintenance for the
Toshiba Personal Computer Libretto 100CT.
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 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: A Note contains general information that relates to your safe
maintenance services.
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.
Be sure to fasten screws securely with the right screwdriver. If a screw is
not fully fastened, it could loosen and create a short circuit, which could
cause overheating, smoke, or fire.
If you replace the battery pack, RTC battery, or backup 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.

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The manual is divided into the following parts:
Chapter 1 Hardware Overview describes the system unit and each FRU.
Chapter 2 Troubleshooting Procedures explains how to diagnose and resolve
FRU problems.
Chapter 3 Tests 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 eight appendices describe the following:
Handling the LCD module
Board layout
Pin assignments
Keyboard scan/character codes
Key layout
Wiring diagrams
BIOS Rewrite Procedures
Reliability

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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 keytop symbol, as it
appears on the keyboard, is printed inboldface type.
Key operation
Some operations require you to simultaneously use two or more keys. We identify
such operations by the keytop symbols separated by a plus (+) sign. For example,Ctrl
+ Pause (Break) means you must hold down Ctrl and at the same time pressPause
(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 typeface
below:
Format complete
System transferred

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Table of Contents
Chapter 1 Hardware Overview
1.1 Features..................................................................................................................1-1
1.2 System Unit Block Diagram....................................................................................1-5
1.3 3.5-inch External FDD............................................................................................1-9
1.4 2.5-inch Hard Disk Drive......................................................................................1-10
1.5 Keyboard..............................................................................................................1-11
1.6 TFT Color LCD....................................................................................................1-12
1.7 Power Supply .......................................................................................................1-14
1.8 Batteries...............................................................................................................1-16
Chapter 2 Troubleshooting Procedures
2.1 Troubleshooting......................................................................................................2-1
2.2 Troubleshooting Flowchart.....................................................................................2-2
2.3 Power Supply Troubleshooting...............................................................................2-6
2.4 System Board Troubleshooting.............................................................................2-14
2.5 FDD Troubleshooting...........................................................................................2-25
2.6 HDD Troubleshooting..........................................................................................2-28
2.7 Keyboard Troubleshooting....................................................................................2-34
2.8 Pointing Device Troubleshooting..........................................................................2-36
2.9 Display Troubleshooting.......................................................................................2-37
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........................................................................................................3-10
3.6 Keyboard Test......................................................................................................3-12

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3.7 Display Test..........................................................................................................3-16
3.8 Floppy Disk Test ..................................................................................................3-20
3.9 Printer Test...........................................................................................................3-22
3.10 Async Test............................................................................................................3-24
3.11 Hard Disk Test.....................................................................................................3-26
3.12 Real Timer Test....................................................................................................3-30
3.13 NDP Test .............................................................................................................3-32
3.14 Expansion Test.....................................................................................................3-33
3.15 Sound Test...........................................................................................................3-35
3.16 Error Code and Error Status Names......................................................................3-36
3.17 Hard Disk Test Detail Status.................................................................................3-39
3.18 Hard Disk Format.................................................................................................3-41
3.19 Head Cleaning......................................................................................................3-46
3.20 Log Utilities..........................................................................................................3-47
3.21 Running Test........................................................................................................3-49
3.22 Floppy Disk Drive Utilities....................................................................................3-51
3.23 System Configuration............................................................................................3-56
3.24 SETUP.................................................................................................................3-58
Chapter 4 Replacement Procedures
4.1 Overview................................................................................................................4-1
4.2 HDD.......................................................................................................................4-8
4.3 Optional Memory Module.....................................................................................4-10
4.4 Keyboard..............................................................................................................4-12
4.5 Display Assembly..................................................................................................4-13
4.6 RTC Battery.........................................................................................................4-17
4.7 System Board, Heat Sink and PC Card Slot..........................................................4-18
4.8 Display Mask........................................................................................................4-20
4.9 FL Inverter Board.................................................................................................4-22
4.10 LCD Module........................................................................................................4-24
4.11 Speaker, Power Switch Board and AccuPoint Board.............................................4-27
4.12 LCD Flexible Cable and Microphone.....................................................................4-30

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4.13 I/O Adapter Board................................................................................................4-35
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 Diagrams.........................................................................................F-1
Appendix G BIOS Rewrite Procedures..........................................................................G-1
Appendix H Reliability...................................................................................................H-1

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Chapter 1
Hardware Overview

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Chapter 1 Contents
1.1 Features..................................................................................................................1-1
1.2 System Unit Block Diagram....................................................................................1-5
1.3 3.5-inch External FDD............................................................................................1-9
1.4 2.5-inch Hard Disk Drive......................................................................................1-10
1.5 Keyboard..............................................................................................................1-11
1.6 TFT Color LCD....................................................................................................1-12
1.6.1 TFT Color LCD Module..................................................................1-12
1.6.2 FL Inverter Board............................................................................1-13
1.7 Power Supply.......................................................................................................1-14
1.8 Batteries...............................................................................................................1-16
1.8.1 Main Battery....................................................................................1-16
1.8.2 Battery Icon.....................................................................................1-16
1.8.3 Battery Charging Control.................................................................1-17
1.8.4 RTC Battery....................................................................................1-17
Figures
Figure 1-1 Front of the computer........................................................................................1-4
Figure 1-2 System unit configuration..................................................................................1-4
Figure 1-3 System unit block diagram.................................................................................1-5
Figure 1-4 3.5-inch FDD...................................................................................................1-9
Figure 1-5 2.5-inch HDD.................................................................................................1-10
Figure 1-6 Keyboard.......................................................................................................1-11
Figure 1-7 TFT color LCD..............................................................................................1-12

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Tables
Table 1-1 3.5-inch FDD specifications...............................................................................1-9
Table 1-2 2.5-inch HDD specifications..............................................................................1-9
Table 1-3 LCD specifications...........................................................................................1-12
Table 1-4 FL inverter board specifications.......................................................................1-13
Table 1-5 Power supply board output rating....................................................................1-15
Table 1-6 Battery specifications........................................................................................1-16
Table 1-7 Time required for quick charges........................................................................1-17
Table 1-8 RTC battery charging/data preservation time...................................................1-17

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1Features
1.1 Features
The computer uses Toshiba's advanced Large Scale Integration (LSI), and Complementary
Metal-Oxide Semiconductor (CMOS) technology extensively to provide compact size,
minimum weight, low power usage and high reliability. This computer incorporates the
following features and benefits:
Microprocessor
The computer is equipped with an Intel®Pentium®processor with
MMX Technology that operates at 166MHz and 1.8/2.5 volts.
Memory
The computer comes with 32MB of Extend DataOut (EDO) DRAM.
HDD
The computer has a 2.5-inch HDD with a capacity of 2.1GB HDD or 3.2GB HDD.
Display
The computer has a 7.1-inch color, Thin Film Transistor (TFT) Liquid Crystal
Display (LCD), that enables display up to 256K colors at a resolution 800 x 480
pixels.
A video controller and 2MB of VRAM enable an external monitor to display 16M
colors at a resolution of 800 x 600 pixels or 64K colors at a resolution of 1024 x
768 pixels.
Keyboard
An-easy-to-use 80/82-key keyboard provides a numeric keypad overlay for fast
numeric data entry or for cursor and page control. The keyboard also includes two
keys that have special functions in Microsoft®Windows®95. It supports software
that uses a 101- or 102-key enhanced keyboard.
Batteries
The computer has two batteries a Lithium-Ion main battery pack and RTC battery
that backs up the Real Time Clock and CMOS memory.
Expansion memory slot
An optional 32MB memory module can be installed in the memory slot.

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Universal Serial Bus (USB)
The USB enables daisy-chain connection of up to 127 USB-equipped devices and
12Mbps serial data transfer. It is designed for easy configuration by a PnP
operating system and provides hot insertion/ejection capability. The USB port is
only on the Enhanced Port Replicator.
External monitor port
The port is available only on the I/O adapter and enables connection of an external
SVGA compatible monitor.
PC card slot
A PC card slot accommodates two 5mm cards (Type II) or one 10.5mm (Type III)
card, which support the PC card Standard. These slots support an external FDD,
16-bit PC cards and CardBus PC cards (32 bit) as well as the Zoomed Video (ZV)
port cards, which are dedicated to high-performance video data transfer such as
MPEG video play back.
AccuPoint
This pointer control stick, located in the right of the display panel, provides
convenient control of the cursor without requiring desk space for a mouse.
Docking interface
A 140-pin, docking interface port enables connection of the I/O adapter or an
optional Enhanced Port Replicator.
The Enhanced Port Replicator has two additional PC card slots that one
accommodates a 10.5mm card (Type III) and one accommodates a 5mm card
(Type II). These slots supportCardBus PC card. The Enhanced PortReplicator
also has PS/2 mouse, PS/2 compatible keyboard, USB, parallel, serial and
external monitor ports.
Infrared port
The infrared port is compatible with Fast InfraRed (FIR) standards enabling
wireless 4Mbps data transfer with Infrared Data Association (IrDA) 1.1 compatible
devices.
Sound system
A Sound BlasterProand Windows Sound System compatible sound system
gives the computer multimedia capability. The sound system is equipped with
speaker, microphone and stereo headphone jack.

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External FDD
A 3.5-inch external FDD is connected to the PC card slot and accommodates both
2HD (1.44MB) and 2DD (720KB) disks.

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The computer is shown in Figure 1-1. The system unit configuration is shown in Figure 1-
2.
Figure 1-1 Front of the computer
Figure 1-2 System unit configuration

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1.2 System Unit Block Diagram
Figure 1-3 is a block diagram of the system unit.
Figure 1-3 System unit block diagram

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The system unit is composed of the following major components:
Intel Pentium processor
Intel 166MHz Pentium processor with MMX Technology.
The math co-processor and 32KB cache memory are integrated into the Pentium.
Standard RAM
•32 MB, four 4M x 16-bit EDO DRAM chips
•3.3 volt operation
•No parity bit
•Access time 60 ns
•Data transfer is 64-bit width
BIOS ROM (Flash EEPROM)
•512 KB, one 512K x 8-bit chip
−256 KB are used for system BIOS
−64 KB are used for VGA-BIOS
−8 KB are used for plug and play data area
−8 KB are used for password security
−16 KB are used for boot strap
−288 KB are reserved
•5 volt operation
•Access time 120 ns
•Data transfer is 8-bit width
Optional memory
One expansion memory slot is available for 32MB memory modules. The 32MB
memory modules consist of four 4M x 16-bit EDO DRAM chips.
•3.3 volt operation
•No parity bit
•Access time 60 ns
•Data transfer is 64-bit width

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System Controller Gate Array
•This gate array has the following functions:
−CPU interface/control
−DRAM control
−PCI master/slave interface
−Write buffer (CPU-DRAM, CPU-PCI, PCI-DRAM)
−Prefetch buffer (CPU-PCI, PCI-DRAM)
−Mobile-PC/PCI support DMA function
−Serial interrupt function
−Power management control
−Suspend/resume control
−CPU stop clock function
−PCI clock stop function
−ACPI support function
I/O & PC Card Controller Gate Array
•This gate array has the following functions:
−One UARTs 16550A equivalent (One SIO is used for SIR.)
−One parallel port control supported ECP
−mini ISA bus control
−PCI bus front end control
−PC card control
−ZV-port support
−CardBus control
−FIR function
−Universal I/O port
−Beep volume
−Speaker control
−RTC One T9934 chip is used
Video Controller
•The NeoMagic NM2160 chip is used. The Video controller incorporates
2MB of video memory using a 128-bit data path.
Keyboard Controller (KBC)
•One M38813S chip is used. This KBC includes the keyboard scan
controller and keyboard interface controller. The KBC controls the internal
keyboard, external keyboard, AccuPoint and PS/2 mouse.
AccuPoint Controller (IPSC)
•One EMEP 010B chip is used.
•This controller provides simultaneous control of the Pointing Device.

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Sound Controller
•One OPL3-SA3 is used.
•The OPL3-SA3 incorporates OPL3 FM synthesizer, Digital Analog
Converter (DAC) and MPU401 MIDIinterface.

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1.3 3.5-inch External FDD
The 3.5inch external FDD is a thin, high performance reliable drive that supports 720KB
(formatted) 2DD and 1.44MB (formatted) 2HD disks. The FDD can be connected to the
PC card slot.
The FDD is shown in Figure 1-4. The specifications for the FDD are listed in Table 1-1.
Figure 1-4 3.5-inch FDD
Table 1-1 3.5-inch FDD specifications
Item 2-MB mode 1-MB mode
Storage capacity (KB)
Unformatted
Formatted 2,000 1,440 1,000 720
Number of heads 2 2
Number of cylinders 80 80
Access time (ms)
Track to track
Average
Head settling time
3
181
15
3
181
15
Recording track density (tpi) 135 135
Data transfer rate (Kbps) 500 250
Rotation speed (rpm) 300 300
Recording method Modified Frequency Modulation (MFM)