Lincoln Electric LN-742 LN-742 Operator's Manual page 39

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PROBLEMS
(SYMPTOMS)
The wire is feeding rough or not
feeding. The drive rolls are turn-
ing.
The drive rolls do not turn when the
gun trigger is pressed. The gas
solenoid activates and arc voltage
is present.
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 throughout this manual
POSSIBLE
1. Check for mechanical restric-
tions in the wire feeding path.
Check the gun and gun compo-
nents.
2. Check the drive roll position and
idle roll pressure.
3. The electrode may be dirty or
rusty.
4. Check for the correct gun liner,
tip, and guide tubes.
1. Check plug J5 on the control
board for loose or faulty con-
nections.
LN-742 & LN-742H
CAUSE
If all recommended possible areas of
misadjustment have been checked
and the problem persists, Contact
your local Lincoln Authorized
Field Service Facility.
CAUTION
RECOMMENDED
COURSE OF ACTION
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