Lincoln Electric SVM 106-A Service Manual page 72

F-8
Troubleshooting Guide –
components. See Wiring Diagrams for troubleshooting of specific circuits.
PROBLEMS
(SYMPTOMS)
Wire feed speed adjustment is
rough. Works only at certain
portions of the speed range.
Ground Lead Protector circuit
tripping.
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 216-383-2531 or 1-800-833-9353.
LN-7 GMA WIRE FEEDER
TROUBLESHOOTING AND REPAIR
See Wiring Diagrams for location of specified
POSSIBLE AREAS OF
MISADJUSTMENT(S)
FUNCTIONAL PROBLEMS (Continued)
1. Ensure setscrew
potentiometer knob is tight.
2. Check for a clogged gun liner or
a mechanical restriction in the
wire feeding path.
1. Ensure all
connections to the work make
tight metal-to-metal contact.
2. Ensure that excess work and
input cables are stored more
than 3 ft (1 m) from the wire
feeder.
3. Is input cable coiled next to the
work cable? Uncoil and loop
back and forth in 3 to 6 ft (1 to
2 m) straight lengths to elimi-
nate the coil.
CAUTION
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
on the 1. Check the resistance of the
potentiometer over the entire
range of travel. The potentio-
meter should adjust from 0 to
10K Ohms. If adjustment is not
smooth and linear, replace per
Wire Feed Speed Potentio-
meter Replacement procedure.
2. The motor or motor brushes
may be faulty. Check the motor
brushes length, and replace
them if they are less than 1/4 in.
in length.
work lead Check for grounded leads in the
wiring harness. Pay particular
attention to the leads connecting
the input cable connector (J101) to
the Control PC board. See Wiring
Diagrams in the Electrical Diagrams
Section.
Observe Safety Guidelines