Lincoln LT-7 Troubleshooting Manual page 15

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Troubleshooting Guide –
components. See Wiring Diagrams for troubleshooting of specific circuits.
PROBLEMS
(SYMPTOMS)
The wire will not feed when the
start switch is pressed. There is
not a voltage indicated on the LT7
voltmeter. The wire does inch up
and down 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 electrical technical troubleshooting assistance before you proceed.Call 216-383-2531 or 1-800-
833-9353
TROUBLESHOOTING AND REPAIR
See Wiring Diagrams for location of specified
FIELD
COURSE OF ACTION
FUNCTIONAL PROBLEMS
1. If light 2M on the logic board is
lit the ground lead protector has
tripped. Make sure the LT7 head
or electrode is NOT contacting
the LT7 frame or control box.
Note that conductive dirt or shav-
ings can cause the ground lead
protector to trip. Remove power to
unit and clear fault.
2. While pressing the start switch
observe light 2B. It should be
lit. If not the start switch (S5) or
associated wires may be faulty.
See wiring diagram.
LT-7 TRACTOR
RECOMMENDED SHOP
COURSE OF ACTION
1. If light 2B is on when the start
CAUTION
Observe Safety Guidelines
detailed in the beginning of this manual.
switch is pressed and light 2M
does NOT light then the logic
board may be faulty.
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