OHAUS SCOUT, Service Manual

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TABLE OF CONTENTS

CHAPTER 1 INTRODUCTION

1.1 Introduction ............................................................................................. 1-1
1.2 Service Facilities ..................................................................................... 1-1
1.3 Tools and Test Equipment Required ...................................................... 1-2

1.3.1 Special Tools and Test Equipment List .......................................... 1-2
1.3.2 Standard Tools and Test Equipment List ........................................ 1-2

1.4 Test Masses Required ............................................................................ 1-2
1.5 Specifications .......................................................................................... 1-3

CHAPTER 2 THEORY OF OPERATION

2.1 Balance Operation .................................................................................. 2-1

2.1.1 Operation ........................................................................................ 2-1

2.1.1.1 Turning the Balance ON ............................................................ 2-1

2.2 Transducer Operation ............................................................................. 2-2
2.3 Printed Circuit Board Circuit Description ................................................ 2-3

2.3.1 Power Supply .................................................................................. 2-3
2.3.2 ON/Off Circuitry .............................................................................. 2-3

2.3.2.1 Turn On Circuitry ....................................................................... 2-3
2.3.2.2 Turn Off Circuitry ....................................................................... 2-3

2.3.3 Low Voltage Detector ..................................................................... 2-4
2.3.4 Temperature A/D Converter ........................................................... 2-4
2.3.5 Full Bridge Weight A/D Convertor ................................................... 2-4
2.3.6 Half Bridge Emulator ....................................................................... 2-5
2.3.7 Microprocessor U1 .......................................................................... 2-5
2.3.8 EEPROM U6 ................................................................................... 2-5
2.3.9 Display Driver U7 ............................................................................ 2-5

CHAPTER 3 TROUBLESHOOTING

3.1 Troubleshooting ...................................................................................... 3-1
3.2 Diagnostic Guide .................................................................................... 3-1

3.2.1 Diagnosis ........................................................................................ 3-1

3.3 Error Codes ............................................................................................ 3-4

CHAPTER 4 MAINTENANCE PROCEDURES

4.1 Preventive Maintenance ......................................................................... 4-1

4.1.1 Preventive Maintenance Checklist .................................................. 4-1

4.2 Testing .................................................................................................... 4-2

4.2.1 Operational Test ............................................................................. 4-2

4.2.1.1 Segment Display Test ............................................................... 4-2

4.2.2 Calibration ....................................................................................... 4-3

4.2.2.1 Calibration Masses .................................................................... 4-3
4.2.2.2 Calibration Procedure ................................................................ 4-3

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