Troubleshooting Guide; Pc Board Troubleshooting Procedure - Lincoln Electric DC-650 PRO IM463-A Operator's Manual

TROUBLE
A. Input contactor chatters.
B. Machine input contactor does
not operate.
C. Machine input contactor
operates, but no output when
trying to weld.
D. Machine has high output and
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
CAUSE
1. Faulty input contactor.
2. Low line voltage.
3. Pilot transformer (T2) misconnected.
1. Supply line fuse blown.
2. Contactor power circuit dead.
3. Broken power lead.
4. Wrong input voltage.
5. Primary thermostats open.
6. Open input contactor coil.
7. Power "On/Off" switch (S1) not
closing.
1. Electrode or work lead loose or
broken.
2. Open main transformer (T1)
primary or secondary circuit.
3. Defective Control P.C. Boards.
4. Output terminals switch set
wrong or faulty.
5. Secondary thermostat open.
1. Fault in leads 75, 76, or 77.
2. Open in feedback circuity.
CAUTION
– –
20
WHAT TO DO
1. Refer to wiring diagram &
check related leads.
2. Check input power.
3. Check input connection
1. Replace if blown-look for reason first.
2. Check pilot transformer T2 and
associated leads.
3. Check input voltage at contactor.
4. Check voltage against instructions.
5. Check for overheating; make sure fan is
operating and there is no obstruction to free
air flow. Replaces faulty thermostat.
6. Replace coil.
7. Replace switch.
1. Repair connection.
2. Repair.
3. Replace. See P.C. Board
Troubleshooting Procedure.
4. Check setting/operation of the
Output Terminals switch.
5. Check for overheating; make sure fan is
operating and there is no obstruction to free
air flow. Replaces faulty thermostat.
1. Check wiring.
2. Check control and protection PC Baord
wiring. With input power off, check for
continuity between (+) output stud and lead
and 1J12 on the control board. Also check for
continuity between GMAW/FCAW (-) output
stud and 3J12 on the control board. Finally,
check for continuity between SMAW/SAW (-)
output stud and 2J12. Repair if necessary.
instructions.