Troubleshooting and repair – Lincoln Electric POWER MIG 255 SVM144-B User Manual
Page 52
POWER MIG 255
TROUBLESHOOTING AND REPAIR
F-14
F-14
c. If any of the voltages tested are
incorrect, check for loose or broken
leads between the test points and
the main transformer.
d. If ALL the voltages tested are incor-
rect or missing, go to step 16.
17. Test for correct nameplate input
voltage between the H1 lead at the
ON/OFF POWER SWITCH to H2 or
H3 (H5 if connected for 575 VAC) at
the reconnect panel. Voltage tested will
vary depending on input voltage
connection. See wiring diagram for test
point locations.
a. If the voltage test is incorrect,
-check for loose or broken leads
between the reconnect panel and
the ON/OFF POWER SWITCH.
-test the ON/OFF POWER
SWITCH for proper operation.
b. If the correct nameplate voltage is
being applied to the main trans-
former and one or more of the sec-
ondary voltages are missing or are
incorrect, the main transformer may
be faulty. Replace.
14. Locate the following leads on plug J9
on the M19248 snubber PC board and
on plug J5 on the G3521 control PC
board. See Figure F.1.
G3521:
M19248:
15. Turn the machine ON.
16. Make the following voltage tests at plug
J9 on the M19248 snubber PC board
and at plug J5 on the G3521 control PC
board.
a. Turn the machine OFF between
each test.
b. Carefully insert the meter probes
into the back of each Molex plug
pin cavity to perform the test.
MAIN TRANSFORMER TEST (continued)
PLUG
LOCATION
3J5
LEAD
206
PLUG
LOCATION
2J9
6J9
LEAD
208S
209S
FROM
LEAD
208S
(2J9 on
M19248)
208S
(2J9 on
M19248)
209S
(6J9 on
M19248)
TO
LEAD
209S
(6J9 on
M19248)
206
(3J5 on
G3521)
206
(3J5 on
G3521)
EXPECTED
VOLTAGE
56VAC
28VAC
28VAC