Toshiba T3400 User manual

T3400/T3400CT Maintenance Manual
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1.1 Features
The Toshiba T3400/T3400CT is one of the lightest and most advanced portable computers
available. Utilizing advanced technology and high-speed components, the T3400/T3400CT
offers excellent display legibility, battery operation and IBM PC/AT compatibility. The
T3400/T3400CT system unit consists of the following features:
❑Microprocessor
The T3400/T3400CT uses an SL Enhanced Intel 486SX-33 microprocessor that
operates at 33 MHz, 3.3 Volts.
❑Cache memory
The T3400/T3400CT has an 8 Kilobyte (KB) cache memory stored in the i486SX
microprocessor.
❑Disk storage
The T3400/T3400CT has an internal 120 Megabyte (MB) Hard Disk Drive (HDD)
with an average access time of 17 milliseconds. An external 3.5-inch Floppy Disk
Drive (FDD) supports 2HD floppy disks (1.44 MB) and 2DD floppy disks (720 KB).
❑Memory
The T3400/T3400CT comes standard with 4 MB of CMOS Random-Access Memory
(RAM) 3.3 Volts. This includes 640 KB of conventional memory and 3,456 KB of
extended memory which can be utilized as expanded memory compatible with Lotus/
Intel/Microsoft-Expanded Memory Specifications (LIM-EMS).
❑Monochrome LCD (T3400)
A high-resolution, Liquid Crystal Display (LCD) displays 640 x480 pixels with a
64-level gray scale.
The T3400 internal display controller supports Video Graphics Array (VGA) func-
tions on the internal display and Super VGA (SVGA) functions on the external
display.
❑TFT color LCD (T3400CT)
A high-resolution, Thin-Film Transistor (TFT) full-color LCD displays 640 x 480
pixels. The T3400CT internal display controller supports VGA functions for internal
display and Super VGA (SVGA) functions for external display.
❑Keyboard
An easy-to-use 82/84-key keyboard includes a keypad overlay for fast numeric data
entry or cursor and page control. The computer keyboard supports software that uses
a 101- or 102-key enhanced keyboard.

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❑Batteries
The T3400/T3400CT has three batteries: a main battery, backup battery, and Real-
Time Clock (RTC) battery.
❑Personal Computer Memory Card International Association (PCMCIA) card slot
The T3400/T3400CT has one PCMCIA slot for installation of an MiNC Toshiba card
modem or other industry-standard PCMCIA release 2.0 card.
❑Parallel port
The T3400/T3400CT parallel interface port serves two purposes. The port can be
used to connect a Centronics-compatible printer or an external 5.25-inch floppy disk
drive.
❑RS-232C port
The T3400/T3400CT has one 9-pin serial interface port.
❑External 3.5-inch FDD port
The T3400/T3400CT has one external 3.5-inch FDD port.
❑Port replicator port
The T3400/T3400CT has one port replicator port which enables connection of an
optional port replicator or external monitor adapter. The port replicator allows
connection of an optional PS/2 keyboard, PS/2 mouse, and external monitor.
❑Memory module slot
The T3400/T3400CT has one slot for optional installation of a Toshiba memory
module.
❑Accupoint
The T3400/T3400CT has a pointer control stick in the center of the keyboard.

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The T3400/T3400CT Personal Computer is shown in Figure 1-1. T3400/T3400CT system
configuration is shown in Figure 1-2.
Figure 1-1 T3400/T3400CT Personal Computer
Figure 1-2 T3400/T3400CT System Unit Configuration

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1.2 System Unit Block Diagram
Figure 1-3 is a block diagram of the T3400/T3400CT system unit.
Figure 1-3 T3400/T3400CT System Board Block Diagram

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The T3400/T3400CT system board includes the following major components:
❑i486SX-33 CPU
❑Super Integration (SI) T9901 Gate Array (GA), which houses the following:
•Two Direct Memory Access Controllers (DMAC): 82C37
•Two Programmable Interrupt Controllers (PIC): 82C59
•One Programmable Interval Timer (PIT): 82C54
•One Floppy Disk Controller (FDC): TC8565
•One Serial Input/Output Controller (SIO): TC8570
•One Variable Frequency Oscillator (VFO): TC8568
•One Input/Output (I/O) Controller
•One Printer Port Controller
•One Speaker Controller
❑RTC
One T9934 chip with 128 bytes of memory is used. Fourteen bytes of memory are
used for the calendar and clock, and the remaining 114 bytes for system configura-
tion data.
OSC (X2) generates 32.768 KHz for the RTC.
❑Keyboard Controller (KBC)
One M37452M4 chip is used. This KBC includes the keyboard scan controller and
keyboard interface controller. The KBC controls the internal keyboard, Accupoint
(pointer control stick), external keyboard, and PS/2 mouse.
❑The following memories:
Standard RAM: 4 MB
Cache memory: 8 KB (inside CPU)
BIOS ROM: 128 KB (96 KB are used)
This ROM contains Initial Reliability Test (IRT), Basic
Input Output System (BIOS), and video BIOS.
Video RAM: 256 KB
Optional cards can be used to expand memory to a maximum of 20 MB.
❑VGA display controller (WD90C24)
This controller controls the internal VGA display and external SVGA- compatible
display.

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❑Clock Generator receives 14.31818 MHz (X3) and generates the following frequen-
cies:
•33 MHz for the CPU
•14.7477 MHz for the Communications (COM) port
•24 MHz for the FDC and VFO
•16 MHz is used for system controller GA
•14.31818 MHz is used for the SI T9901 GA
❑Gate Arrays
System Controller GA
This GA has the following functions:
•CPU Controller
•Memory Controller
-DRAM Controller
-Compatible Bus Interface Controller
•SMI Controller
•VL Bus Controller
•Bus Controller
-Compatible Bus Interface Controller
-Compatible Access Controller
-DMAC Controller
-I/O Controller
•Address Latch Controller
-32 to 16-Bit Controller
-Address Latch
-DMA Address Generator
-Refresh Address Generator
•I/O Register
-Compatible I/O Port
-Saving Register Controller data in AutoResume (resume mode)
-Toshiba Special Register
•Processing Speed Controller
•Data Bus Change Controller
•Data Latch
PCMCIA Controller GA
This GA has the following functions:
•Memory Card Controller
-PCMCIA IC Card Controller
-Toshiba Modem Card Controller

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1.3 External 3.5-inch Floppy Disk Drive
The 3.5-inch FDD is a thin, high-performance, reliable drive that supports 720-KB (format-
ted) 2DD and 1.44-MB (formatted) 2HD 3.5-inch floppy disks.
The FDD is shown in Figure 1-4. Specifications for the FDD are provided 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 2,000 1,000
Formatted 1,311 737
Number of heads 2 2
Number of cylinders 80 80
Access time (ms)
Track to track 3 3
Average 181 181
Head settling time 15 15
Recording track density (tpi) 135 135
Data transfer rate (Kbps) 500 250
Rotation speed (rpm) 300 300
Recording method Modified Frequency Modulation (MFM)

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T3400/T3400CT Maintenance Manual
1.4 2.5-inch Hard Disk Drive
The HDD is a random-access, non-volatile storage device. It has a non-removable 2.5-inch
magnetic disk and mini-Winchester type magnetic heads.
The T3400/T3400CT supports a 120 MB HDD.
The HDD is shown in Figure 1-5. Specifications for the HDD are provided in Table 1-2.
Figure 1-5 2.5-inch HDD
Table 1-2 2.5-inch HDD Specifications
Items (CP2124) (MK2124FC)
Storage capacity (MB)
Formatted 121.6 130.1
Number of disks 2 2
Data heads 4 4
Data surfaces 4 4
Tracks per surface 1,123 1,155
Sectors per track 53 (+1) 55 (+1)
Bytes per sector 512 512
Access time (ms)
Track to track 10 5
Average 17 17
Maximum 35 36
Rotation speed (rpm) 3,743 3,200
Data transfer rate (bps)
To/from media 18 M 15.3 M
Interleave 1:1 1:1
Recording method 2-7 RLL/ 1-7 RLL
1-7 RLL

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1.5 Keyboard
The 82-key (USA) or 84-key (European) keyboard is mounted on the system unit. The
keyboard is connected to the KBC on the system board via a 19-pin flat cable. The keyboard
is shown in Figure 1-6.
See Appendix F for optional configurations.
Figure 1-6 Keyboard

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1.6 Monochrome LCD
The monochrome LCD is composed of an LCD module, a Fluorescent Lamp (FL), and an
FL inverter board.
1.6.1 Monochrome LCD Module
The T3400 monochrome LCD supports 640 x480 pixels with a video controller and 64
levels of gray. The video controller includes the functions of the VGA and SVGA.
The LCD receives vertical and horizontal synchronizing signals, 8-bit data signals (4-bit
upper block data signal and 4-bit lower block data signal), and shift clock for data transmis-
sion. All signals are CMOS-level compatible.
The sidelit LCD is shown in Figure 1-7 and its specifications are provided in Table 1-3.
Figure 1-7 Monochrome LCD
Table 1-3 Monochrome LCD Specifications
Item Specifications
Number of dots (dots) 640 x 480
Dot pitch (mm) 0.24 (W) x 0.24 (H)
Display area (mm) 176.8 (W) x 132.6 (H)
Contrast 18:1 (typically)
FL current (mA) 4.0 (full-power mode)
FL frequency (KHz) 44

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1.6.2 Monochrome Fluorescent Lamp (FL) Inverter Board
The FL inverter board supplies the high-frequency current needed to illuminate the FL.
Specifications for the FL inverter board are provided in Table 1-4.
Table 1-4 Monochrome FL Inverter Board Specifications
Item Specifications
Input Voltage (VDC) 10
Power (W) 3.0
Voltage (VAC) 1,100 (r.m.s)
Output Current (mA) 5.0 (r.m.s)
Frequency (KHz) 44

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1.7 TFT Color LCD
The TFT Color LCD contains an LCD module, an FL, and an FL inverter board.
1.7.1 TFT Color LCD Module
The T3400CT TFT color LCD supports 640 x 480 pixels with an internal display controller
and 256K colors for graphics and characters. This controller includes the functions of VGA
and SVGA for external display.
The T3400CT’s LCD receives 9-bit data signals, data-enable signals, and shift clock for data
transmission. All signals are CMOS-level compatible.
The TFT LCD is shown in Figure 1-8. Specifications for the LCD are provided in Table 1-5.
Figure 1-8 TFT Color LCD
Table 1-5 TFT Color LCD Specifications
Item Specifications
Number of dots (dots) 640 x480
Dot pitch (mm) 0.249 (W) x0.249 (H)
Display area (mm) 159.36 (W) x 119.52 (H)
Contrast 55:1 (minimum)
FL current (mA) 5.0
FL frequency (KHz) 33

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1.7.2 TFT Color Fluorescent Lamp (FL) Inverter Board
The FL inverter board supplies high-frequency current to light the LCD Fluorescent Lamp.
Specifications for the FL inverter are provided in Table 1-6.
Table 1-6 FL Inverter Board Specifications
Item Specifications
Input Voltage (VDC) 10
Power (W) 3
Output Voltage (VAC) 1,100 (r.m.s)
Current (mA) 5.0
Frequency (KHz) 44

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1.8 Power Supply
The power supply provides five kinds of voltages to the system board. The power supply has
one microprocessor which operates at 500 Hz and performs the following functions:
1. Determines if the AC adapter or battery is connected to the computer.
2. Detects DC output and circuit malfunctions.
3. Controls the LED icon and speaker.
4. Turns the battery charging system on and off.
5. Determines if the power can be turned on and off.
6. Determines if the battery is fully charged or low.
7. Calculates remaining battery capacity.
Power supply output ratings are specified in Table 1-7.
Table 1-7 Power Supply Output Ratings
DC Regulation Maximum
Use for Name voltage tolerance current Ripple
(V) (%) (mA) (mV)
System logic, FDD, HDD, VCC +5 ±5 3,500 100
Display DSPV +10.8/+15 ±5 260 150
RS-232-C Flash ROM 12V +12 ±5 70 240
RAM, CPU B3V +3.3 ±5 1,170 66
RS-232C -9V -9 15 15 180

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1.9 Batteries
The T3400/T3400CT has three types of batteries:
❑Main battery pack
❑Backup battery
❑RTC battery
Battery specifications are provided in Table 1-8.
Table 1-8 Battery Specifications
Battery name Material Output voltage Capacity
Main battery pack Lithium-Ion 10.8 V 3,000 mAH
Backup battery Nickel Metal Hydride 1.2 V 1,200 mAH
RTC battery Lithium-Vanadium 3.0 V 50 mAH
1.9.1 Main Battery
The removable main battery pack is the primary power source when the AC adapter is not
attached. The main battery recharges the backup battery when system power is on. The
backup and main battery maintain the state of the computer system when AutoResume is
enabled.
❏Battery Indicator
The battery indicator is located on the front left of the computer. The indicator color desig-
nates status of the removable battery pack and AC adapter.
Orange The battery is being charged. (AC adapter is attached.)
Green The battery is fully charged. (AC adapter is attached.)
No light The AC adapter is disconnected from the computer or is connected, but
cannot charge the battery for one of the following reasons:
❍The battery is extremely hot. Allow the computer and the battery to reach
room temperature before attempting to charge the battery.
❍The battery is almost fully discharged and will not begin
charging until a few minutes after the AC adapter is connected.
❍The AC adapter is not receiving power.

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1.9.2 Battery Charging Control
Battery charging is controlled by a microprocessor mounted on the power supply. The
microprocessor turns charging on or off and detects a full charge when the AC adapter and
main battery pack are attached to the computer. The system charges the main battery pack
using quick or trickle charge.
❏Battery Charging
When the AC adapter is attached, there are two types of charge: quick charge when the
system is powered off and trickle charge when powered on. Table 1-9 gives quick and trickle
charging time requirements.
Table 1-9 Time Required For Main Battery Charges
Charge Charging time
Quick charge About 3 hours
(power off)
Trickle charge About 8 hours
(power on)
If one of the following occurs, the quick charge process stops.
1. The main battery pack becomes fully charged.
2. The main battery pack or AC adapter is removed.
3. The main battery pack or AC adapter output voltage is abnormal.
4. The charge current is abnormal.
When the main battery pack is fully charged and the AC adapter is attached, the power supply
microprocessor changes quick charge to trickle charge.
1.9.3 Backup Battery
The backup battery maintains data for AutoResume (resume mode). The power source used
to back up AutoResume data is determined according to the following priority:
AC adapter > Main battery pack > Backup battery
The backup battery is charged by the main battery pack or AC adapter when the system is
powered on. Table 1-10 shows the charging time and data preservation period of the backup
battery.

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Table 1-10 Backup Battery Charging/Data Preservation Time
Backup Battery Time
Charging Time Power On 3 Hours
Power Off (with AC Adapter) Doesn’t charge
Power Off (Without AC Adapter) Doesn’t charge
Data preservation period (full charge) 8 Hours
1.9.4 RTC Battery
The RTC battery provides power to keep the current date, time, and other setup information
in memory while the computer is turned off. Table 1-11 shows the charging time and data
preservation period of the RTC battery.
Table 1-11 RTC Battery Charging/Data Preservation Time
RTC Battery Time
Charging Time Power On 48 Hours
Power Off Doesn’t charge
Data preservation period (full charge) 1 month

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2.1 Troubleshooting
Chapter 2 describes how to determine if a Field Replaceable Unit (FRU) is causing a malfunc-
tion. FRUs covered are:
1. Power Supply
2. System Board(s)
3. Floppy Disk Drive
4. Hard Disk Drive
5. Keyboard
6. Display
Diagnostics Disk operations are described in Chapter 3 and detailed replacement procedures
are given in Chapter 4.
The following tools are necessary for troubleshooting:
1. T3400/T3400CT Diagnostics Disk
2. Phillips-head screwdriver (2 mm)
3. Toshiba MS-DOS system disk(s)
4. 2DD or 2HD formatted work disk for FDD testing
5. Cleaning kit for FDD troubleshooting
6. Printer port LED
7. RS-232-C wraparound connector
8. Printer wraparound connector
9. Multimeter
10. External 5.25-inch FDD
11. External monitor adapter
12. External monitor

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2.2 Troubleshooting Flowchart
Use the flowchart in Figure 2-1 as a guide to determine which procedures to execute. Before
going through the flowchart steps, verify the following:
❑Ask the user if a password is registered, and if it is, ask him or her to enter the pass-
word. If the user has forgotten the password, connect the printer port wraparound
board (F31PRT), then turn the POWER switch on. The computer will override the
password function by erasing the current password.
❑Verify with the customer that Toshiba MS-DOS is installed on the hard disk. Non-
Toshiba operating systems can cause the computer to malfunction.
❑Make sure all optional equipment is disconnected.
❑Make sure the FDD is empty.

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Figure 2-1 Troubleshooting Flowchart