Lincoln Electric Invertec STT II Operator's Manual page 24

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Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
Major physical or electrical damage
is evident
Machine has no open circuit voltage.
Wire feeds ok.
Machine has no welding output (no
open circuit voltage) and the wire
feeder does not feed wire when the
gun trigger is pulled.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your
Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
TROUBLESHOOTING
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. Contact your local Lincoln
Authorized Field Service
Facility.
1. Check the control cable between
the feeder and the STT II II unit.
Make sure the #2 and #4 leads
are intact.
2. Put a jumper wire between Pins
"C" and "D" on the 14 pin MS
connector. If normal open circuit
voltage (85VDC.) is restored
then the problem is in feeder
control cable or the wire feeder.
1. The 42VAC circuit breaker CB1
may be tripped. Reset if neces-
sary.
2. Put a jumper between pins "A"
and "C" on the 5 pin MS connec-
tor located on the LN742 wire
feeder. If wire feeds check the
gun trigger. Repair or replace if
necessary.
3. Check for the presence of 42AC
at pins "K" and "I" on the 14 pin
MS connector. If the 42VAC is
present and the feeder does not
work the problem is in the feeder
control cable(s) or the wire feed-
er.
CAUTION
INVERTEC STT II
RECOMMENDED
COURSE OF ACTION
If all recommended possible areas
of misadjustment have
checked and the problem persists,
Contact your local Lincoln
Authorized Field
Facility.
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been
Service