Troubleshooting & repair – Lincoln Electric POWER MIG 255 SVM144-B User Manual
Page 62
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POWER MIG 255
TROUBLESHOOTING & REPAIR
F-24
F-24
4. Verify that the capacitors have
completely discharged with a volt-
ohmmeter.
5. Disconnect plugs J6 from the G3521
control board and J9 from the M19248
snubber PC board. This electrically
isolates the SCR bridge assembly.
See Figure F.6.
TEST PROCEDURE
1. Disconnect main AC input power to the
machine.
2. Remove the case top and side panels
with a 3/8 in. nutdriver.
3. Remove the tool tray with a 5/16 in. nut-
driver.
ACTIVE SCR RECTIFIER ASSEMBLY TEST (continued)
FIGURE F.6 — CONTROL BOARD MOLEX PLUG LOCATIONS FOR G3521 PC CONTROL BOARD.
J6
J5
J3
J8
J1
J4
J2
J9
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