Troubleshooting & repair – Lincoln Electric INVERTEC POWER WAVE 450 SVM112-B User Manual
Page 130
POWER WAVE 450
F-70
F-70
TROUBLESHOOTING & REPAIR
FIELD EFFECT TRANSISTOR/SWITCH BOARD TEST
(continued)
TABLE F.4 – SWITCH BOARD 3 RESISTANCE TEST TABLE (Continued)
Apply
Apply
Positive
Negative
Test
Test
Probe to
Probe to
Test
Repair
Next
Terminal
Terminal
Result
Conclusion
Action
Procedure
12C
3T
Less than
OK
None
Continue
100 ohms
Greater Open
Replace
4
Snubber
than 1K
Switch
Resistor
ohm
Boards
Test
3T
12C
Greater
OK
None
Continue
than 1K
ohm
Less than
Shorted
Replace 4
Snubber
100 ohms
Switch
Resistor
Boards
Test
12C
405
Greater
OK
None
Continue
than 1K
ohm
Less than
Shorted
Replace 4
Snubber
100 ohms
Switch
Resistor
Boards
Test
405
12C
Less than
OK
None
Continue
100 ohms
Greater
Open
Replace 4
Snubber
than 1K
Switch
Resistor
ohm
Boards
Test
9C
406
Less than
OK
None
Continue
100 ohms
Greater
Open
Replace 4
Snubber
than 1K
Switch
Resistor
ohm
Boards
Test
406
9C
Greater
OK
None
Continue
than 1K
ohm
Less than
Shorted
Replace 4
Snubber
100 ohms
Switch
Resistor
boards
Test
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).