Lincoln Electric 9535 Operator's Manual page 15

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PROBLEMS
(SYMPTOMS)
C. Machine input contactor closes
but has no or low output. Open
circuit voltage should be 67 to 71
volts.
D. Machine has maximum output
but no control.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
TROUBLESHOOTING
Observe all Safety Guidelines detailed througout this manual
POSSIBLE CAUSE
FUNCTION PROBLEMS
1. Electrode or work lead loose or
broken.
2. Open transformer primary or
secondary circuit.
3. Supply line fuse blown.
4. Input line grounded causing
single phase input.
5. Input leads not connected to
contactor.
6. Latching resistor, R3, open.
7. Control circuit problems.
1. Possible defective power SCR.
2. Possible defective control board.
IDEALARC R3R 375-I, 500-I AND 600-I
1. Repair connections.
2. Repair.
3. Replace blown fuse – check fuse
4. Repair input to machine.
5. Connect input lead.
6. a. Replace.
7. See Troubleshooting Procedures
1. Remove all gate leads G1, G2
2. See PC board Troubleshooting
CAUTION
RECOMMENDED
COURSE OF ACTION
size.
b. Check leads to the resistor
and repair if defective.
– Power Silicon Controlled
Rectifier.
and G3 at PC board connector
J4. If welder has any open circuit
voltage, power SCR is defective.
See Troubleshooting Procedures
Section J.
Procedures Section A
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