Removal And Replacement Procedures; Flashing Diode (D1) & Field Diode (D2) Removal And Replacement Procedure - Lincoln Electric Fleet 650 Service Manual

LINCOLN ELECTRIC

Removal And Replacement Procedures

FLASHING DIODE (D1) & FIELD DIODE (D2) REMOVAL AND REPLACEMENT
PROCEDURE
Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized
repairs performed on this equipment may result in danger to the technician or machine operator and will
invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety
notes and precautions detailed throughout this manual. If for any reason you do not understand the test
procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department
for electrical troubleshooting assistance before you proceed. Call 1-888-935-3877.
TEST DESCRIPTION
This procedure will aid the technician in the removal and replacement of the
Field Diode (D2).
MATERIALS NEEDED
3/8" Nutdriver
Dow Corning 340 Heat Sink Compound (Lincoln Part #T12837)
Wiring Diagram
REMOVAL PROCEDURE
1. Turn off the engine on the Fleet 650 machine.
2. Perform the Case Cover Removal Procedure.
3. Perform the Chopper Module Capacitor Discharge Procedure.
4. Label and disconnect leads 232P, 232N, 232M and 204C from the flashing diode (D1) and leads
201A, 200A, 204B, 5H and 3A from the field diode (D2). See Figure F.31. See Wiring Diagram.
5. Using a 3/8" nutdriver, remove the nut and insulating washer securing each diode to the PCB
bracket. See Figure F.32.
6. The flashing diode (D1) and/or field diode (D2)
REPLACEMENT PROCEDURE
1. Apply a thin coating of Dow Corning 340 heat sink compound to the mating surfaces of the diodes.
2. Carefully position the new flashing diode (D1) and/or field diode (D2) onto the PCB bracket.
3. Using a 3/8" nutdriver, attach the nut and insulating washer securing each diode to the PCB bracket.
4. Connect leads 232P, 232N, 232M and 204C to the flashing diode (D1) and leads 201A, 200A, 204B,
5H and 3A to the field diode (D2).
5. Perform the Case Cover Replacement
6. Perform the Retest After Repair Procedure.
can now be removed and replaced.
See Wiring Diagram.
Procedure.
Fleet™ 650 Service Manual
Flashing Diode (D1) and/or
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