
TABLE OF CONTENTS - TROUBLESHOOTING AND REPAIR
F-1
F-1
RANGER® 225 GXT
Troubleshooting & Repair Section
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Section F
How to Use Troubleshooting Guide .......................................................................................F-2
PC Board Troubleshooting Procedures .................................................................................F-3
Troubleshooting Guide .................................................................................................F4 - F-14
Test Procedures
Rotor Voltage Test .........................................................................................................F-15
Rotor Resistance Test ...................................................................................................F-17
Auxiliary and Field Winding Test ...................................................................................F-21
Output Rectifier Bridge Test ..........................................................................................F-25
Charging Circuit Test .....................................................................................................F-27
Engine Throttle Adjustment Test....................................................................................F-29
Oscilloscope Waveforms
Normal Open Circuit Voltage Waveform (115 VAC Supply) ..........................................F-33
Typical DC Weld Output Waveform (CV Mode) – Machine Loaded .............................F-34
Typical DC Weld Output Waveform (CC Mode) – Machine Loaded .............................F-35
Typical AC Weld Output Waveform – Machine Loaded ................................................F-36
Abnormal Open Circuit Weld Voltage Waveform (CV Mode, one diode open).............F-37
Abnormal Open Circuit DC Weld Voltage Waveform ....................................................F-38
Normal Open Circuit Weld Voltage Waveform (CV Mode)............................................F-39
Normal Open Circuit DC Weld Voltage Waveform........................................................F-40
Normal Open Circuit AC Weld Voltage Waveform ........................................................F-41
Replacement Procedures
Brush Removal and Replacement.................................................................................F-43
Printed Circuit Board Removal and Replacement.........................................................F-47
Output Rectifier Bridge Removal and Replacement .....................................................F-51
Engine Rotor Removal and Replacement (Kit S20788)................................................F-55
Retest After Repair...............................................................................................................F-60
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