Lincoln Electric SVM154-A Service Manual page 52

F-7
Observe all Safety Guidelines detailed throughout this manual.
PROBLEMS
(SYMPTOMS)
The wire feed speed does not
change when welding current is
established.
The voltmeter does not function
properly. The welding may vary
from normal performance. The wire
feeds properly.
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 1-800-833-9353.
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TROUBLESHOOTING AND REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
FUNCTION PROBLEMS (Continued)
1. The "run-in" and "weld" wire
feed speeds may be set at the
same value.
2. Check the current sensing reed
switch leads and connectors for
loose or faulty corrections. See
the Wiring Diagram.
1. Make sure the dip switch set-
tings on the control board are
correct for the power source
being used. See Welding
Power Source Selection.
2. Make sure the voltage sense
leads are connected.
A. Lead #67 has continuity
(zero ohms) to the electrode.
B. Lead #21 has continuity
(zero ohms) to the work
piece.
CAUTION
RECOMMENDED
COURSE OF ACTION
1. Check the current sensing reed
2. The control board may be
1. The control board may be
2. The display board may be
LN-10
switch for proper operation.
A. While not welding the volt-
age at pins 3J1 to 4J1
should be approximately 12
VDC. The reed switch
should be open. If the 12
VDC is missing either the
reed switch is stuck closed
or the control board is defec-
tive.
B. While welding current is
flowing the voltage at pins
3J1 to 4J1 should be
approximately 0 VDC. The
reed switch should be
closed. If the voltage is not
at or near 0 VDC, the reed
switch is faulty.
faulty.
faulty.
defective.
F-7