Lincoln Electric SVM138-A Service Manual page 87

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TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
The arc voltage appears to rise too
slowly or stubs or blasts at the start
of a weld. Once started the weld-
ing is good.
NOTE: Pulse Power 500 operation
with a filter kit may exhibit these
symptoms.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
216-383-2531 or 1-800-833-9353.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
STARTING PROBLEMS
1. Adjust the "start" trimmer on the
voltage PC board. It should be
slightly higher than the weld
voltage. See Starting Charac-
teristics in the Operation section
of this manual.
3. Put the Lincoln power source in
the "Machine Control" mode.
Jumper the "BYPASS" pins on
the LN-9 GMA voltage PC
board. Adjust the weld voltage
from the power source for the
process being used. If the cor-
rect voltage cannot be set, the
power source may be faulty.
4. Check for correct control cable
connections to the power supply.
CAUTION
LN-9 GMA Wire Feeder
Observe Safety Guidelines
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. The voltage PC board may be
faulty. Replace.
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