Lincoln LT-7 Troubleshooting Manual page 18

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Troubleshooting Guide –
components. See Wiring Diagrams for troubleshooting of specific circuits.
PROBLEMS
(SYMPTOMS)
The wire will not inch down. The
wire inches up properly. When the
start switch is pressed the wire
feeds up instead of down.
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. Check the connections between
the power source and LT7 for
loose or incorrect connections.
2. Check the leads connected to
the variable voltage board for
loose or faulty connections.
3. While pressing the inch down
switch observe light 3A on the
variable voltage board.
• If light 3A is NOT lit check
leads #21 and #67 for conti-
nuity to the voltage board.
4. If while pressing the inch down
switch light 3A does light also
check light 2E on the logic
board.
• If light 3A and 2E are both lit
the control board may be
faulty.
• If light 3A is lit but light 2E is
NOT lit the logic board may
be faulty.
LT-7 TRACTOR
RECOMMENDED SHOP
COURSE OF ACTION
1. Check lead #21 for continuity
2. Check lead #67 for continuity
CAUTION
Observe Safety Guidelines
detailed in the beginning of this manual.
(zero ohms) to "work".
(zero ohms) to electrode.
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