Fluke ScopeMeter 123 Service Manual page 5

6 Disassembling the Test Tool ............................................................. 6-1
6.1. Introduction................................................................................................ 6-3
6.2. Disassembling Procedures ......................................................................... 6-3
6.1.1 Required Tools .................................................................................... 6-3
6.2.2 Removing the Battery Pack ................................................................. 6-3
6.2.3 Removing the Bail ............................................................................... 6-3
6.2.4 Opening the Test Tool ......................................................................... 6-3
6.2.5 Removing the Main PCA Unit............................................................. 6-5
6.2.6 Removing the Display Assembly......................................................... 6-6
6.2.7 Removing the Keypad and Keypad Foil.............................................. 6-6
6.3 Disassembling the Main PCA Unit ............................................................. 6-6
6.4 Reassembling the Main PCA Unit .............................................................. 6-8
6.5 Reassembling the Test Tool........................................................................ 6-8
7 Corrective Maintenance ..................................................................... 7-1
7.1 Introduction................................................................................................. 7-3
7.2 Starting Fault Finding. ................................................................................ 7-4
7.3 Charger Circuit............................................................................................ 7-4
7.4 Starting with a Dead Test Tool ................................................................... 7-6
7.4.1 Test Tool Completely Dead................................................................. 7-6
7.4.2 Test Tool Software Does not Run. ...................................................... 7-7
7.4.3 Software Runs, Test Tool not Operative ............................................. 7-7
7.5 Miscellaneous Functions............................................................................. 7-8
7.5.1 Display and Back Light ....................................................................... 7-8
7.5.2 Fly Back Converter.............................................................................. 7-9
7.5.3 Slow ADC............................................................................................ 7-10
7.5.4 Keyboard.............................................................................................. 7-11
7.5.5 Optical Port (Serial RS232 Interface).................................................. 7-11
7.5.6 Channel A, Channel B Voltage Measurements ................................... 7-12
7.5.7 Channel A Ohms and Capacitance Measurements .............................. 7-13
7.5.8 Trigger Functions................................................................................. 7-14
7.5.9 Reference Voltages.............................................................................. 7-15
7.5.10 Buzzer Circuit .................................................................................... 7-15
7.5.11 Reset ROM Circuit (PCB version <8 only)....................................... 7-16
7.5.12 RAM Test .......................................................................................... 7-16
7.5.13 Power ON/OFF .................................................................................. 7-16
7.5.14 PWM Circuit...................................................................................... 7-17
7.5.15 Randomize Circuit ............................................................................. 7-17
7.6 Loading Software........................................................................................ 7-17
8 List of Replaceable Parts................................................................... 8-1
8.1 Introduction................................................................................................. 8-3
8.2 How to Obtain Parts.................................................................................... 8-3
8.3 Final Assembly Parts .................................................................................. 8-4
8.4 Main PCA Unit Parts .................................................................................. 8-6
8.5 Main PCA Parts .......................................................................................... 8-7
8.6 Accessory Replacement Parts ..................................................................... 8-24
8.7 Service Tools............................................................................................... 8-24
9 Circuit Diagrams................................................................................. 9-1
9.1 Introduction................................................................................................. 9-3
9.2 Schematic Diagrams.................................................................................... 9-4
Contents
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