Troubleshooting & repair, Troubleshooting guide, Caution – Lincoln Electric SQUARE WAVE TIG 255 SVM100-A User Manual
Page 47
SQUARE WAVE TIG 255
F-6
TROUBLESHOOTING & REPAIR
Observe Safety Guidelines
detailed in the beginning of this manual.
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
The ammeter displays a very high
value (greater than 316 amps)
when the machine is not loaded.
Machine may have low or no out-
put.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
None.
RECOMMENDED
COURSE OF ACTION
1.
The shunt leads (#221 and
#222) may be loose or open.
Check the red and white twist-
ed pair from the shunt to the
control board. Refer to wiring
diagram.
2.
The Control board may be
faulty. If the shunt leads have
continuity (zero ohms) to the
control board, pins 1J7 and
2J7, then replace the control
board. See pin locations in
Figure F.1 at end of this Guide.
OUTPUT PROBLEMS
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 216-383-2531 or 1-800-833-9353.
CAUTION