Lincoln LT-7 Troubleshooting Manual page 25

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Troubleshooting Guide –
components. See Wiring Diagrams for troubleshooting of specific circuits.
PROBLEMS
(SYMPTOMS)
The power source output contactor
does NOT "drop out". The power
source output terminals are always
electrically hot.
The welding and travel do not stop
when the stop switch is 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. With the LT7 at idle (not feeding
wire) observe light 2K on the
logic board. It should not be on.
If light 2K IS on the logic board
may be faulty.
2. If light 2K is NOT lit (with the
LT7 at idle) locate and remove
lead #2 on the 1CR relay. If the
power source output contactor
drops out the 1CR relay may be
faulty.
3. If the power source contactor
stays "ON" ( output terminals
electrically hot) with #2 lead
removed from 1CR, the prob-
lem is in the control cable or the
power source.
1. While pressing the stop switch
observe light 2C. If light 2C is
on the logic board may be faulty.
2. If light 2C is NOT lit (while
pressing the stop switch) check
the stop switch (S6) and associ-
ated leads.
LT-7 TRACTOR
RECOMMENDED SHOP
COURSE OF ACTION
CAUTION
Observe Safety Guidelines
detailed in the beginning of this manual.
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