Lincoln Electric SQUARE WAVE TIG 355 Service Manual page 59

F-7
Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
The machine shuts off (pilot light
goes out and the fans stop) when
the Arc Start Switch or Amptrol is
activated.
The 115VAC receptacle does not
work. The machine operates nor-
mally.
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 technical troubleshooting assistance before you proceed.
Call 1-888-935-3877.
TROUBLESHOOTING AND REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. The input voltage may be too
high (more than 10% over rated).
2. The Arc Start switch may be
faulty. Check or replace.
1. The circuit breaker CB1 may
have opened.
sary.
2. Check for the presence of
115VAC at the receptacle.
CAUTION
SQUARE WAVE TIG 355
COURSE OF ACTION
1. Perform the Static & Active
SCR Bridge Tests.
2. Perform the Power Board Test.
3. Perform the Control Board
Test.
4. Shunt may be faulty or over-
heated. Check for loose con-
nections and replace shunt if
necessary.
1. The circuit breaker may be
Reset if neces- faulty. Test or replace.
2. If the fans are running, check
the receptacle and the associat-
ed wiring.
F-7
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