Fluke 43B - Corrective Maintenance

7-1
Chapter 7
Corrective Maintenance
Title Page
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............................................................................. 7-7
7.5.1 Display and Back Light ....................................................................... 7-7
7.5.2 Fly Back Converter.............................................................................. 7-8
7.5.3 Slow ADC............................................................................................ 7-9
7.5.4 Keyboard.............................................................................................. 7-10
7.5.5 Optical Port (Serial RS232 Interface).................................................. 7-11
7.5.6 Input Channel 1 and 2 Voltage Measurements.................................... 7-11
7.5.7 Ohms and Capacitance Measurements ................................................ 7-12
7.5.8 Trigger Functions................................................................................. 7-13
7.5.9 Reference Voltages.............................................................................. 7-14
7.5.10 Buzzer Circuit.................................................................................... 7-14
7.5.11 Reset ROM Line (ROMRST)............................................................ 7-14
7.5.12 RAM Test .......................................................................................... 7-14
7.5.13 Power ON/OFF.................................................................................. 7-15
7.5.14 PWM Circuit...................................................................................... 7-15
7.5.15 Randomize Circuit ............................................................................. 7-15