OHAUS T71P, Service Manual

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TABLE OF CONTENTS
CHAPTER 1 GETTING STARTED
Page No.
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 T71P and T71XW: Top and Bottom Housing ............................................................1-2
1.5 Specifications.............................................................................................................1-4
1.6
Hardware Setup or Disassembly ...............................................................................1-5
1.6.1 Connecting the Scale Base’s Load Cell .............................................................1-5
1.6.2 Jumper
Connections ..........................................................................................1-6
1.6.3 RS232 Interface .................................................................................................1-6
1.7 Operation ...................................................................................................................1-7
1.7.1 Power Supply .....................................................................................................1-7
1.7.2 Overview of the Controls ....................................................................................1-7
1.7.3 Overview of the Display Indicators .....................................................................1-7
1.7.4 Overview of the Control Functions .....................................................................1-8
1.7.5 Menu
Setup ........................................................................................................1-9
1.7.6 Language Menu Setup .....................................................................................1-12
1.8 Calibration................................................................................................................1-13
1.8.1 Zero Calibration ................................................................................................1-13
1.8.2 Span Calibration ...............................................................................................1-14
1.8.3 3-point Linearity Calibration..............................................................................1-15
1.8.4 5-point Linearity Calibration..............................................................................1-16
1.8.5 Calibration
Test ................................................................................................1-17
1.8.6 Geographical Adjustment Factor ......................................................................1-17
1.9 RS232 Interface Connection....................................................................................1-18
1.9.1 Setting Communications Parameters ...............................................................1-18
1.9.2 Interface
Commands ........................................................................................1-19
1.9.3 Output Format ..................................................................................................1-20
1.10 Legal For Trade (LFT) .............................................................................................1-21
CHAPTER 2 TROUBLESHOOTING
2.1 Introduction ................................................................................................................2-1
2.2 Visual Inspection........................................................................................................2-1
2.3 Diagnostic Guide .......................................................................................................2-2
2.2.1 Diagnosis............................................................................................................2-2
CHAPTER 3 MAINTENANCE PROCEDURES
3.1 Preventive Maintenance ............................................................................................3-1
3.1.1 Preventive Maintenance Checklist .....................................................................3-1
3.2 Replacement of Major Components ..........................................................................3-1
3.2.1 Main Printed Circuit Board (PCB) Replacement.................................................3-2
3.2.1 Display Printed Circuit Board (PCB) Replacement.............................................3-3
3.2.3 Membrane
Switch Replacement.........................................................................3-4
CHAPTER 4 TESTING
4.1. Testing .......................................................................................................................4-1
4.2 Power
Test.................................................................................................................4-1
4.3 Performance Tests Using a Scale Base ....................................................................4-1
Ohaus Corporation www.ohaus.com 1 7000 Series T71 Indicators Service Manual