Commodore 128: Troubleshooting and Repair

✍ Scribed by John Heilborn

• Publisher: Howard W. Sams
• Year: 1988
• Tongue: English
• Leaves: 162
• Edition: 1
• Category: Library

✦ Synopsis

In his most recent book, Commodore 128 Troubleshooting & Repair, Mr. Heilborn provides both experienced and novice users with a nuts-and-bolts look at the
Commodore 128—how it works, what can go wrong, why, and how to make repairs.

The first book to address C-128 troubleshooting and repair, it discusses:
• The Commodore 128's design and electrical components
• Systems and subsystems
• Troubleshooting and step-by-step diagnostic techniques
• How to make repairs
• Preventive maintenance tips

✦ Table of Contents

Preface ix

Introduction: A New Generation xi

Chapter I-A Look at the Commodore 128 1
System Design 1
Introduction to Troubleshooting Techniques 4

Chapter 2-Commodore 128 Systems and Subsystems 11
The Microprocessors 12
Memory 17
Input/Output 20
Summary 31

Chapter 3-Troubleshooting Techniques 33
Identifying Problem Areas 33
The Single-Path Method 34
Tools and Test Equipment 37
Repairs: Guidelines and Cautions 41
Soldering Techniques 43
Finishing Up 46

Chapter 4-Digital Logic Circuits 47
Logic Gates 47
Combining Logic Functions 49
Electrical Characteristics 51
Digital Memory Devices 52
Microprocessors 55

Chapter 5-Troubleshooting Techniques:
System Doesn't Work 57
System Does Nothing 57
System Turns On, No Display, or Bad Display 59
System Turns On, No Keyboard Response 66
Strange or Inappropriate Messages or Garbage
on Screen 69

Chapter 6-Troubleshooting Techniques:
Poor Video or No Video 75
No Picture at All 75
No Color or Wrong Colors 79
Picture Rolls or Tilts 83

Chapter 7-Troubleshooting Techniques:
Defective Keyboard 87
Keyboard Doesn't Work at All 87
Keyboard Generates the Wrong Characters 91

Chapter 8-Troubleshooting Techniques:
Input/Output Problems 97
Disk Drive Problems 97
Cassette Problems 100
Game Controller Problems 102

Chapter 9-Preventive Maintenance 107
Looking for Trouble 107
Protecting the Life of Your Computer 107
Peripheral Devices 110
Disk Drives 114
A Few Final Notes 116

Appendix A-Integrated Circuit Pinouts 117
Appendix B-Board Layout 127
Appendix C-Input/Output Ports 129
Appendix D-System Specifications 131
Appendix E-Keyboard Codes 133

Glossary 135

✦ Subjects

Microcomputers -- Maintenance and repair;Commodore 128 (Computer)