Lincoln Electric POWER MIG SVM170-A Service Manual page 48

F-8
Observe all Safety Guidelines detailed throughout this manual.
PROBLEMS
(SYMPTOMS)
No control of wire feed speed. Other
machine functions are normal
There is no wire feed when gun trig-
ger is pulled. Normal open circuit
voltage is present.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric
Service Department for technical troubleshooting assistance before you proceed. Call 1-888-935-3877.
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TROUBLESHOOTING AND REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WIRE FEEDING PROBLEMS
1. The wire feed speed control
may be dirty. Rotate several
times and check if problem is
resolved.
1. Check for adequate wire supply.
2. If the drive rolls are turning then
check for a mechanical restric-
tion in the wire feed path.
3. The gun liner may be clogged.
Check or replace.
4. If the drive rolls are NOT turning
when the gun trigger is pulled
then contact your local Lincoln
Electric Authorized Field Service
Facility.
CAUTION
POWER MIG 255C
RECOMMENDED
COURSE OF ACTION
1. The Wire Speed Control poten-
tiometer may be faulty. Check or
replace. See Wiring Diagram.
2. Perform the Wire Drive Motor
and Tachometer Feedback
Test.
3. The control board may be faulty.
Replace.
1. Perform the Wire Drive Motor
and Tachometer Feedback
Test.
2. The Wire Feed Control poten-
tiometer may be faulty. Check or
replace. See Wiring Diagram.
3. The control board may be faulty.
Replace.
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