Lincoln LT-7 Troubleshooting Manual page 14

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Troubleshooting Guide –
components. See Wiring Diagrams for troubleshooting of specific circuits.
PROBLEMS
(SYMPTOMS)
The wire will not feed and the cir-
cuit breaker trips when the inch or
start switches are pressed.
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. Reset the circuit breaker and
observe lights 1C and 1D on
the control board with the unit at
idle. (Not attempting to feed
wire). Light 1C should be OFF
and light 1D should be ON. If
both lights are OFF remove
power and check F101 field
fuse. (1/2amp).
2. If both lights are ON the control
board may be faulty.
3. The following conditions may
cause the F101 fuse to fail.
•Faulty wire drive motor
•Incorrect welding procedure.
•A low impedance across the
arc voltage sensing leads (#21
and #67).
•A defective control board.
LT-7 TRACTOR
RECOMMENDED SHOP
COURSE OF ACTION
1. If when at idle light 1D is ON
CAUTION
Observe Safety Guidelines
detailed in the beginning of this manual.
and light 1C is OFF then perform
the Wire Drive Motor Test .
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