Pc Board Troubleshooting Procedures - Lincoln Electric 10372 Service Manual

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4. Test the machine to determine if the
failure symptom has been corrected by
the replacement PC board.
NOTE: It is desirable to have a spare
(known good) PC board available for PC
board troubleshooting.
NOTE: Allow the machine to heat up so
that all electrical components can reach
their operating temperature.
5. Remove the replacement PC board and
substitute it with the original PC board
to recreate the original problem.
NOTE: Do not substitute boards that show
physical damage.
a. If the original problem does not
reappear by substituting the original
board, then the PC board was not
the problem. Continue to look for
bad connections in the control
TROUBLESHOOTING ND REP IR
POWER W VE 455/POWER FEED 10
wiring harness, junction blocks, and
terminal strips.
b. If the original problem is recreated
by the substitution of the original
board, then the PC board was the
problem. Reinstall the replacement
PC board and test the machine.
6. Always indicate that this procedure was
followed when warranty reports are to
be submitted.
NOTE: Following this procedure and writ-
ing on the warranty report, "INSTALLED
AND SWITCHED PC BOARDS TO VERIFY
PROBLEM," will help avoid denial of legiti-
mate PC board warranty claims.
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