OHAUS EB SERIES, Service Manual

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TABLE OF CONTENTS
EB Series Scales Service Manual i Ohaus Corporation www.ohaus.com
CHAPTER 1 GETTING STARTED
Page No.
1 Introduction ..............................................................................................................1-1
1.1 Service Facilities ......................................................................................................1-1
1.2 Tools and Test Equipment Required ........................................................................1-2
1.2.1 Standard Tools and Test Equipment .................................................................1-2
1.2.2 Special Tools ....................................................................................................1-2
1.3 Calibration Masses Required ...................................................................................1-2
1.4 Service Strategy .......................................................................................................1-2
1.5 Specifications ...........................................................................................................1-3
1.6
S
cale Settings ..........................................................................................................1-4
CHAPTER 2 DIAGNOSIS
2. Diagnosis .................................................................................................................2-1
2.1 Scale Setup and Examination ..................................................................................2-1
2.2 Preliminary Checks ..................................................................................................2-1
2.3 Troubleshooting Tables ............................................................................................2-1
2.4 EB Series Scales Error Code Table .........................................................................2-5
2.5 Testing the AC Adapter ............................................................................................2-6
2.6 Testing the Membrane Switch ..................................................................................2-6
2.7 Testing the Load Cell Assembly ...............................................................................2-7
2.7.1 Resistance Test ................................................................................................2-7
2.7.2 Excitation and Output Voltage Test ...................................................................2-7
2.8 Testing the Main PC Board ......................................................................................2-9
2.8.1 Main PC Board Voltage Measurements ............................................................2-9
2.8.2 Simulator Testing ..............................................................................................2-9
2.8.2.1 General Load Test.................................................................................. 2-10
2.8.2.2 Calibration Test ...................................................................................... 2-10
2.9 Testing the Battery ................................................................................................. 2-11
2.9.1 Precautions for Battery Handling ..................................................................... 2-11
2.9.2 Battery Tests ................................................................................................... 2-11
CHAPTER 3 REPAIR PROCEDURES
3. Repair Procedures ...................................................................................................3-1
3.1 Removing Top Housing ............................................................................................3-1
3.2 Replacing The Membrane Switch .............................................................................3-2
3.3 Main Printed Circuit Board .......................................................................................3-4
3.3.1 Main Printed Circuit Board Replacement ..........................................................3-4
3.3.2 Display Printed Circuit Board Replacement .......................................................3-7
3.3.3 LCD Replacement .............................................................................................3-8
3.4 Replacing the Load Cell Assembly (with Frame) ......................................................3-9
3.5 Replacing the Load Cell Component ...................................................................... 3-11
3.5.1 Overload Protection Stop Adjustment ............................................................. 3-12
3.6 Replacing the Battery ............................................................................................. 3-14
CHAPTER 4 FINAL TESTING & CALIBRATION
4.1. Performance Tests ...................................................................................................4-1
4.1.1 Segment Display Test .......................................................................................4-1
4.1.2 Repeatability Test .............................................................................................4-1
4.1.3 Off-Center Load Test ........................................................................................4-3
4.1.4 Linearity Test ....................................................................................................4-4
4.2 Calibration ................................................................................................................4-6
4.2.2 Span Calibration ...............................................................................................4-6