Lincoln Electric INVERTEC POWER WAVE 450 SVM112-B Service Manual page 134

F-74
Apply
Positive
Test
Probe to
Terminal
12
1/3
12
401/403
405/407
9
402/404
406/408
NOTE: K ohm = ohm reading multiplied by 1000.
NOTE: Always make sure that all four Switch Boards are changed at the same time. Never
mix an old style (different part number) Switch Board with a new style (new part
number).
TROUBLESHOOTING & REPAIR
IGBT/SWITCH BOARD TEST (Continued)
TABLE F.6 (Continued)
Apply
Negative
Test
Probe to Test
Terminal Result
1/3 Less than
100 ohms
Greater
than 1K
ohms
12 Greater
than 1K
ohms
Less than
1k ohms
401/403 Greater
405/407 than 1K
ohms
Less than
1k ohms
12 Less than
100 ohms
Greater
than 1K
ohms
402/404 Less than
406/408 100 ohms
Greater
than 1K
ohms
9 Greater
than 1K
ohms
Less than
1k ohms
POWER WAVE 450
Repair
Conclusion Action
OK None
Open Replace
Switch
Boards
OK None
Shorted Replace
Switch
Boards
OK None
Shorted Replace
Switch
Boards
OK None
Open Replace
Switch
Boards
OK None
Open Replace
Switch
Boards
OK None
Shorted Replace
Switch
boards
F-74
Next
Procedure
Continue
Snubber
Resistor
Test
Continue
Snubber
Resistor
Test
Continue
Snubber
Resistor
Test
Continue
Snubber
Resistor
Test
Continue
Snubber
Resistor
Test
Continue
Snubber
Resistor
Test