Compaq LTE Elite Manual

Notice
The information in this guide is subject to change without notice.
Compaq Computer Corporation shall not be liable for technical or editorial
errors or omissions contained herein; nor for incidental or consequential
damages resulting from the furnishing, performance, or use of this
material.
This guide contains information protected by copyright. No part of this
guide may be photocopied or reproduced in any form without prior written
consent from Compaq Computer Corporation.
Copyright 1994 Compaq Computer Corporation.
All rights reserved. Printed in the U.S.A.
Compaq, Deskpro, LTE, Contura
Registered U.S. Patent and Trademark Office.
LTE Elite, SmartStation, and MiniStation are trademarks of Compaq Computer
Corporation.
Microsoft and MS-DOS are registered trademarks of Microsoft Corporation.
Windows is a trademark of Microsoft Corporation.
The software described in this guide is furnished under a license agreement
or nondisclosure agreement. The software may be used or copied only in
accordance with the terms of the agreement.
Product names mentioned herein may be trademarks and/or registered
trademarks of their respective companies.
MAINTENANCE AND SERVICE GUIDE
COMPAQ LTE ELITE FAMILY OF PERSONAL COMPUTERS
COMPAQ SMARTSTATION
First Edition (March 1994)
Part Number 194061-001

Preface
USING THIS GUIDE
This Maintenance And Service Guide is a troubleshooting reference for
servicing the Compaq LTE Elite Family of Personal Computers, the Compaq
SmartStation, the Compaq MiniStation/EN, and the Compaq MiniStation/TR.
The guide is organized into the following parts:
o Part 1: Compaq LTE Elite Computer (Chapters 1 through 5)
o Part 2: Compaq SmartStation (Chapters 6 through 10)
o Appendices
Compaq Computer Corporation reserves the right to make changes to the
Compaq LTE Elite Family of Personal Computers and its options without
notice.
SYMBOLS AND CONVENTIONS
The following format conventions distinguish elements of the text
throughout this guide:
o When keys must be pressed at the same time, the action is represented by
the key names and the plus (+) symbol. For example, Ctrl+Alt+Delete.
o The names of files are presented in uppercase, as shown here:
FILENAME.
o The names of commands or directories are presented in uppercase type as
shown here: COMMAND or DIRECTORY. Commands that are to be entered at the
system prompt are shown on a separate line.
o When you are asked to type something without pressing the Enter key, you
are directed to "type" the information.
o When you need to type information and press the Enter key, you are
directed to "enter" the information.
The following words and symbols mark special messages throughout this
guide:
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> WARNING <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Text set off in this manner indicates that failure to follow directions in
the warning could result in bodily harm or loss of life.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> CAUTION <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Text set off in this manner indicates that failure to follow directions
could result in damage to equipment or loss of information.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
IMPORTANT: Text set off in this manner presents clarifying information or
specific instructions.
NOTE: Text set off in this manner presents commentary, sidelights, or
interesting points of information.
TECHNICIAN NOTES
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> WARNING <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Only authorized technicians trained by Compaq Computer Corporation should
attempt to repair this equipment. All troubleshooting and repair procedures
are detailed to allow only subassembly/module level repair. Because of the
complexity of the individual boards and subassemblies, no one should
attempt to make repairs at the component level or to make modifications to
any printed circuit board. Improper repairs can create a safety hazard. Any
indication of component replacement or printed circuit board modifications
may void the warranty or exchange allowances.
To properly ventilate the computer or the expansion base, allow at least 3
inches (7.62 cm) of clearance at the back and sides of the units.
To avoid the risk of electric shock or damage to the computer or expansion
base, ensure that all power sources (including the battery pack in the
computer) are disconnected before removing and replacing internal parts.
Compaq SmartStation. The Compaq SmartStation expansion base is designed
for connection to a grounded (earthed) electrical outlet. The grounding
type plug is an important safety feature. To avoid the risk of electric
shock or damage to the equipment, do not disable this feature.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
LOCATING ADDITIONAL INFORMATION
The following documentation is available to support the Compaq LTE Elite
Family of Personal Computers and its options.
o Documentation included with the computer:
- Online USER'S GUIDE
- QUICK SETUP card
- BEYOND SETUP GUIDE
o COMPAQ SMARTSTATION INSTALLATION AND OPERATIONS GUIDE
o COMPAQ MINISTATION INSTALLATION GUIDE
o COMPAQ SERVICE QUICK REFERENCE GUIDE
o Compaq QuickFind
o Compaq Service Advisories and Bulletins

Chapter 1 - Compaq LTE Elite Product Overview
Introduction
This chapter is an overview of the Compaq LTE Elite Family of Personal
Computers and covers the following topics:
o Serial number
o System overview
o Models and features
o Controls and LEDs
o Connectors
o Functional descriptions
o Docking options
o Running Computer Setup
o Reprogrammable flash ROM
o Power Management
o Security
1.1 Serial Number
The computer serial number should be provided to Compaq whenever requesting
information or ordering spare parts. The serial number is located above the
connectors behind the input/output (I/O) connector cover.

1.2 System Overview
The Compaq LTE Elite has the following upgradeable assemblies:
o Hard drive
o Display assembly
o Processor board
o RAM memory expansion board
The Compaq LTE Elite is designed to dock in one of the following options:
o Compaq SmartStation (Figure 1-1)
o Compaq LTE Lite Desktop Expansion base (with a Compaq LTE Lite Upgrade
Adapter)
o Compaq MiniStation/EN or Compaq MiniStation/TR
When docked in one of these options, the computer has the following
additional features:
o A single connection that provides multiple pass-through connections to
options such as a printer, monitor, and other external equipment
o Built-in network and SCSI-2 capability (on the Compaq SmartStation and
Compaq MiniStations only)
o Two internal drive bays (on the expansion bases only)
o Two full size 8-/16-bit Industry Standard Architecture (ISA) expansion
slots (on the expansion bases only)

Computer power is supplied through one of the following sources:
o An internal battery pack
o The computer's internal AC adapter when connected to the power cord
(Figure 1-2)
o The computer's internal AC adapter when docked in a convenience base
o The 198-pin external options connector when docked in an expansion base
(provides DC power)
o Automobile Adapter (provides DC power)

1.3 Models And Features
Models
Table 1-1 lists the Compaq LTE Elite models and model-specific features.
Table 1-1. Compaq LTE Elite Computer Models
===========================================================================
Internal
Model Display Processor Cache RAM Hard Drive
===========================================================================
4/75CX 9.5" Color TFT 486 DX4/75 MHz 16 KB 8 MB 340 or 510 MB
4/50CX 9.5" Color TFT 486 DX2/50 MHz 8 KB 8 MB 340 MB
4/40CX 8.4" Color TFT 486 DX2/40 MHz 8 KB 4 MB 170 or 340 MB
4/50E 9.5" Mono TFT 486 DX2/50 MHz 8 KB 4 MB 250 MB
4/40C 9.5" Color STN 486 DX2/40 MHz 8 KB 4 MB 170 MB
===========================================================================
Features
All models of the computer have the following features:

o Internal AC adapter
o Upgradeable SL Enhanced Intel486 microprocessors
o User upgradeable display with integrated trackball
o Local bus graphics and graphics accelerator with 1024 x 768 external
video support
o Simultaneous display capability
o Removable 2.5-inch hard drive
o Reprogrammable flash ROM (Section 1.9)
o 4 MB system RAM expandable to 20 MBs or 8 MB system RAM expandable to 24
MBs. The following memory expansion boards are available (Section 1.6):
-4MB
-8MB
-16MB
o 1.44 MB/720 kilobyte (and 1.2 MB Japanese standard), 3.5-inch diskette
drive
o Internal dynamic speaker
o Internal 101-/102-key compatible keyboard (Enhanced III type with 12
function keys)
o External keyboard/mouse support
o External numeric keypad support
o Enhanced parallel port (EPP 1.9)
o PCMCIA slot, capable of handling one of the following card combinations:
- Two PCMCIA Type I or Type II cards
- One PCMCIA Type III card
o Nickel metal hydride (NiMH) battery pack
o Battery power management features, including the following:
- Four levels of power management
- Advanced Power Management (APM)
- Standby
- Hibernation
- Screen save
- Hard drive idle
- PCMCIA slot power management
- Battery gauge
- Auxiliary battery (to protect data during battery pack replacement)
o AC power management features including the following:
- Standby
- Hard drive idle
- Screen save
o Saving of changes to hotkey settings when computer is turned off
o Electronic security features

o The following preinstalled software:
- MS-DOS and Microsoft Windows
- TabWorks utility (alternative to Program Manager)
- Computer Setup, Computer Checkup, Power Management, and Security
Management utilities
- Automatic PCMCIA configuration utilities for MS-DOS and Windows
- Windows-based online documentation
- Plug and Play BIOS
- MS-DOS- and Windows-based shutdown capability (for closing out
applications and turning off computer)
- Microsoft Video for Windows Runtime Version
- Adaptec 6360 SCSI drivers
- Universal Netware Client for simplified setup of a Netware network
- Intel Ethernet drivers and TI Token Ring drivers for networks other
than Netware
- Western Digital WIN graphics drivers
- Logitech Trackball drivers
1.4 Controls And Leds
This section covers the computer controls and LEDs (Figure 1-3).

1. Caps lock LED
2. Display switch
3. Scroll lock LED
4. Num lock LED
5. Power switch
6. Standby button
7. Power/standby LED
8. Hard drive LED
9. Diskette drive LED
10. Power/standby LED
11. Battery LED
12. Trackball
13. Trackball buttons
14. Display control slide(s)
LEDs
Table 1-2 lists the function of the LEDs.
Table 1-2. LEDs
===========================================================================
LED Name Status Indication Location Color
===========================================================================

Power/ On Power on LED on top of unit Green
standby Flashing Standby (active when display is
open). Identical LED on
front of unit (active
when display is closed).
---------------------------------------------------------------------------
Battery On Battery Front of unit Orange
State charging
Flashing LowBatt 1
at one
per
second
Flashing LowBatt 2
at two
per
second
---------------------------------------------------------------------------
Hard Drive On Hard drive Front of unit Green
Activity being
accessed
---------------------------------------------------------------------------
Diskette On Diskette Front of unit Green
Drive drive being
Activity accessed
---------------------------------------------------------------------------
Scroll On Scroll lock Top of unit Green
Lock selected
---------------------------------------------------------------------------
Caps Lock On Caps lock Top of unit Green
selected
---------------------------------------------------------------------------
Num Lock On Num lock Top of unit Green
selected
===========================================================================
Display Switch
The computer has a display switch mounted on the power interface board
(PIB) located near the display hinge. When the display is closed, this
switch activates the front-mounted power/standby LED and simultaneously
deactivates the display and the top-mounted LEDs.
Trackball
The computer has an integrated PS/2 style trackball located on the display
bezel. The trackball is disabled whenever an external mouse is connected to
the keyboard/mouse connector. The trackball buttons are located on the back
side of the display.
1.5 Connectors
This section covers the I/O pass-through connectors on the computer
(Figure 1-4). Refer to Appendix A for connector pin assignments.

1. AC power
2. Automobile Adapter
3. Serial
4. 198-pin external options
5. Keyboard/mouse
6. Parallel
7. External monitor
8. Numeric keypad
9. PCMCIA
AC Power Connector
When the computer is docked in the convenience base and the convenience
base is turned on, AC power is applied to the computer's AC power
connector. (The 198-pin connector carries all other signals between the two
units.)
Automobile Adapter Connector
The computer has an automobile adapter connector that accepts an 18.5 volt,
1.73 amp DC input from the Automobile Adapter. This connector is covered
by an access door (Figure 1-5).

NOTE: The automobile adapter converts 12 volts DC from the automobile to
18.5 volts DC for use by the computer.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> CAUTION <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
The computer has an access door for the automobile adapter connector that
is designed to allow only one type of power input (AC or DC) to be
connected at a time (Figure 1-5). Do not attempt to defeat this protective
feature of the door or internal damage to the computer may result.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Serial Connector
The serial connector supports the serial interface which meets EIA RS232C
specifications.
198-Pin External Options Connector
The 198-pin external options connector handles the signal interface between
the computer and the expansion base or convenience base.
NOTE: When connected to an expansion base, power to the computer is carried
through the 198-pin connector (DC power).

Keyboard/Mouse Connector
The keyboard/mouse connector can be connected to a PS/2 mouse or an external
enhanced keyboard. Connecting the mouse/keyboard connector to a mouse
disables the integrated trackball, while connecting the mouse/keyboard
connector to an external keyboard disables the internal keyboard.
Parallel Connector
The parallel connector supports the parallel interface which meets
EPP 1.9 specifications.
External Monitor Connector
The external monitor connector provides an output for an external monitor
with a maximum resolution of 1024 x 768 lines.
NOTE: The computer can simultaneously display on an external monitor and
the integrated display panel.
Numeric Keypad
Connecting the numeric keypad connector to an external numeric keypad
disables the embedded numeric keypad feature.
PCMCIA Connector
The computer has a PCMCIA connector accessible through a PCMCIA slot on the
left side of the computer (refer to "PCMCIA Slot" in Section 1.6). The
PCMCIA connector supports the PCMCIA interface which meets PCMCIA 2.1
specifications.
1.6 Functional Descriptions
This section covers functional descriptions of key parts and features of
the computer. For assembly/disassembly instructions for the parts described
in this section, refer to Chapter 4.
System Board

The system board (Figure 1-6) provides the following:
o Connector for removable hard drive [1]
o PCMCIA connector [2] (refer to "PCMCIA Slot")
o Board-to-board connection to the following devices:
- Power interface board (PIB) [3]
- Processor board [4]
- Memory expansion board (on underside of system board)
o Cable connection to the following devices:
- Internal AC power supply board [5]
- Fan [6]
- Internal keyboard [7]
- Display [8]
- Diskette drive [9]
-LED cable assembly for front-mounted LEDs (on underside of system board)

o Battery charging circuitry and battery contacts [10] for battery pack
o External input/output (I/O) connectors (Figure 1-4)
o DC-to-DC power supply (refer to "DC-to-DC Power Supply" in this section)
o 256 Kbyte flashable shared system ROM and keyboard ROM
o 4 or 8 MB base RAM (depending on the model)
o System controller, which provides the following:
- Interface to the processor board for memory management (including
memory refresh)
- Two DMA controllers
- Two interrupt controllers
- Clock generator
- Programmable interval timer
- System management interrupt (SMI) support logic
- Power management features
o Peripheral controller, which provides the following:
- Integrated keyboard controller
- Industry Standard Architecture (ISA) support logic
- Circuit for interfacing to the hard drive
- Control of parallel and serial interfaces, including serial interfaces
for a numeric keypad, mouse/keyboard, and internal trackball
o PCMCIA controller
o Local bus video controller
o Diskette drive controller
o Docking sense logic
o Secondary temperature sensor for controlling the fan (refer to
"Temperature Sensors")
DC-to-DC Power Supply
The DC-to-DC power supply is integrated into the system board. It converts
DC voltage input to regulated 3.3 volts, 5 volts, and 12 volts DC. The DC

voltage input comes from one of the following sources:
o Internal AC power supply
o Battery pack
o Automobile adapter
o 198-pin external options connector (from expansion base)
o Auxiliary battery
To replace the DC-to-DC power supply, the system board must be replaced.
Processor Board
The SL Enhanced Intel486 processor has an integrated coprocessor and is
upgradeable by replacing the processor board (Figure 1-7). The system
automatically adjusts to the new configuration. In addition, the processor
board contains the primary temperature sensor (refer to "Temperature
Sensors").
Some models have a heat sink attached. The computer comes with one of the
following processors:
o 486 DX4/75 MHz
o 486 DX2/50 MHz
o 486 DX2/40 MHz

NOTE: The 75 MHz processor is also available as an upgrade option.
Temperature Sensors
The primary temperature sensor is located on the processor board and the
secondary temperature sensor is located on the system board. These sensors
turn the fan on when the system approaches maximum reliable operating
temperatures.
If the temperature continues to rise, a system management interrupt (SMI)
is generated that creates a pop-up window (depicting a thermometer) to warn
the user of the temperature overload and the unit goes into Standby within
several seconds. If the temperature continues to rise, the computer turns
itself off.
NOTE: The temperature sensors are integrated into the processor board and
the system board. To replace a temperature sensor, the appropriate
board must be replaced.
Power Interface Board (PIB)
The power interface board (PIB) (Figure 1-8) is mounted to the system board
by a 16-pin connector. The PIB provides the following features:

o Numeric keypad connector
o Speaker and speaker amplifier
o Power switch
o Standby button
o Display switch
o The following LEDs:
- Power/standby
- Scroll lock
- Caps lock
- Num lock
Refer to Section 1.4 for more information on the controls and LEDs listed
above.
Memory Expansion Board
The 4 or 8 MB base RAM memory (depending on the model) may be increased by
adding an optional memory expansion board (Figure 1-9). The memory
expansion board plugs directly into the back side of the system board
(Section 4.6).
The system supports the following 3.3 volt memory expansion boards (which
operate at 70ns):

o4MB
o8MB
o16MB
NOTE: Some early memory expansion boards for the Concerto Family of
Personal Computers (option kit numbers 144790-001 and 144790-002)
operate at 80 ns and do not function properly when installed in the
Compaq LTE Elite Family of Personal Computers, which operate at
70 ns. Use only Compaq LTE Elite memory expansion boards
(Table 3-2).
Refer to the table in Section 5.3 for a list of total RAM memory based on
available system memory and memory obtained from the expansion board.
Internal AC Power Supply (AC-to-DC)
The computer is powered by a high-efficiency, board-mounted, internal
AC-to-DC power supply (Figure 1-10). The power supply provides the computer
with an 18.5 volt DC output for running all computer functions, including
charging the internal battery pack.
Fan