Compaq PORTABLE 386 User Manual

Foreword
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 1987, 1989 Compaq Computer Corporation.
All rights reserved. Printed in the USA.
COMPAQ, COMPAQ PORTABLE III, and COMPAQ PORTABLE 386, are trademarks of
Compaq Computer 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.
Microsoft, MS, and MS-DOS are trademarks of Microsoft Corporation.
Product names mentioned herein are for identification purposes only and may be
trademarks and/or registered trademarks of their respective companies.
COMPAQ PORTABLE 386 PERSONAL COMPUTER
MAINTENANCE AND SERVICE GUIDE
Second Edition (August 1989)
First Edition (September 1987)
Assy No. 107536-002
Binder Number 197537-001
Text Number 107538-002
Compaq Computer Corporation requires that all peripheral devices be connected
to this computer/product via shielded cables with metal RFI/EMI connector
hoods.
==============================================================================
WIRE TYPE: Multipaired, overall shielded; Belden #98XX; Alpha #54XX;
or equivalent.
CONNECTOR HOOD: RFI/EMI metal shield; AMP #74517X-X; or equivalent.
==============================================================================
It is important that the chassis ground strap of the peripheral device be
connected to the computer chassis. An Alpha #1221 flat braided strap is
sufficient. The strap is not necessary if a shielded cable connects the two
chassis.
COMPAQ PORTABLE 386 PERSONAL COMPUTER MAINTENANCE AND SERVICE GUIDE is a
troubleshooting guide that can be used as a reference when servicing the
COMPAQ PORTABLE 386 Personal Computer. Compaq Computer Corporation reserves

Compaq PORTABLE 386 Specifications

General

Manufacturer	Compaq
Model	PORTABLE 386
Category	Desktop
CPU	Intel 80386
Clock Speed	20 MHz
Resolution	640 x 400
Operating System	MS-DOS
RAM	2 MB
Storage	40 MB hard drive
Floppy Drive	3.5-inch
Display	LCD

Summary

Chapter 3. Power On Self Test (POST)/Problem Isolation

Chapter 3.1 POST

Explains the Power On Self Test process and components checked by the system.

Chapter 3.2 Preliminary Steps to Problem Isolation

Outlines essential steps to perform before starting problem isolation procedures.

Chapter 3.3 Problem Isolation Flowchart

Provides a flowchart for identifying and correcting problems that may occur during POST.

Chapter 5. Diagnostics Program

Chapter 6. Error Messages and Codes

Chapter 6.2 Power On Self Test Messages

Lists Power On Self Test error messages, beep codes, probable causes, and recommended actions.

Chapter 6.3 Diagnostic Error Codes

Details diagnostic error codes, their descriptions, and actions to resolve them.

Chapter 8. Removal and Replacement Procedures

Chapter 8.2 Preparation Procedure

Chapter 8.3 Keyboard Assembly

Provides instructions for removing the keyboard assembly.

Chapter 8.4 Rear Panel

Details the procedure for removing and replacing the rear panel.

Chapter 8.5 Interface Connector Cover

Chapter 8.6 Microprocessor Cover

Chapter 8.7 System Board Cover

Chapter 8.8 32 Bit Memory/Modem Interface Board

Chapter 8.9 Internal Modems

Chapter 8.10 Second Serial Interface Board (International Only)

Chapter 8.11 Memory Expansion Boards

Chapter 8.12 Memory Upgrade Kit

Chapter 8.13 System ROM

Chapter 8.14 System Board

Details the procedure for removing the system board assembly.

Chapter 8.15 Plasma Display Controller Board

Explains how to remove the plasma display controller board.

Chapter 8.16 Mass Storage Device Assembly

Provides instructions for removing the mass storage device subassembly.

Chapter 8.17 Fixed Disk Drive

Details how to remove the fixed disk drive assembly.

Chapter 8.18 Diskette Drive

Explains how to remove the diskette drive assembly.

Chapter 8.19 Power Supply

Provides instructions for removing the power supply.

Chapter 8.20 Mass Storage Device Enclosure

Details how to remove the mass storage device enclosure.

Chapter 8.21 LED/Speaker Cable, Keyboard Cable, and LED Assembly

Chapter 8.22 Plasma Display

Provides instructions for removing the plasma display.

Chapter 8.23 Plasma Display Filter

Chapter 8.24 Brightness Control Assembly

Chapter 8.25 Display Enclosure

Provides instructions for removing the display enclosure.

Chapter 8.26 Display Power Cable Assembly and Display Data Cable Assembly

Chapter 8.27 Handle and Spreader Plate

Chapter 8.28 Battery

Provides instructions for removing and replacing the computer's lithium battery.

Chapter 8.29 Expansion Unit

Chapter 8.30 300/600 Megabyte Fixed Disk Drive Expansion Unit

Provides preparation steps for removing the 300/600 megabyte fixed disk drive expansion unit.

Power Supply

External Interface Adapter Board

Chapter 9. Jumper and Switch Settings

Chapter 9.2 System Board

Describes the system board's configuration capabilities and jumper functions.

Chapter 9.3 System Board Jumper Settings

Provides detailed settings for system board jumpers.

Chapter 9.4 Compaq Enhanced Color Graphics Board Jumper and Switch Settings

Explains jumper and switch settings for the COMPAQ Enhanced Color Graphics Board.

Chapter 9.5 Serial/Parallel Interface Board Switch Settings

Lists switch settings for the Serial/Parallel Interface Board.

Chapter 9.6 Video Graphics Controller Board

Details jumper settings for the Video Graphics Controller Board.

Chapter 9.7 ESDI External Fixed Disk Drive Controller Board

Lists switch settings for the ESDI External Fixed Disk Drive Controller Board.