Corrective Maintenance - Fluke ScopeMeter 123 Service Manual

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.......................................... 7-11
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) ............................................. 7-15
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

Corrective Maintenance

Title
Chapter 7
Page
7-1