Continued, Troubleshooting & repair, Switch board test (continued) – Lincoln Electric INVERTEC SVM129-B User Manual
Page 74

TROUBLESHOOTING & REPAIR
F-36
F-36
INVERTEC® STT® & STT® II
Apply Positive Apply Negative
Test Probe to
Test Probe to
Terminal
Terminal
Test Result
Conclusion Repair Action
Next Procedure Notes
12
401/403
Greater than OK
None
Continue
1K ohm
Less than
Shorted
Replace both
Snubber Test
100 ohms
switch boards
401/403
12
Less than
OK
None
Continue
100 ohms
Greater than Open
Replace both
Snubber Test
1K ohm
switch boards
9
402/404
Less than
OK
None
Continue
100 ohms
Greater than Open
Replace both
Snubber Test
1K ohm
switch boards
402/404
9
Greater than OK
None
Continue
1K ohm
Less than
Shorted
Replace both
Snubber Test
100 ohms
switch boards
SWITCH BOARD TEST (continued)
NOTE: K ohm = ohm reading multiplied by 1000.
NOTE: Always make sure that switch boards are changed in matched pairs. Never mix an old style (different
part number) switch board with a new switch board (new part number).
TABLE F.5 – SWITCH BOARD RESISTANCE TEST (continued)
8. Reconnect all wiring harness leads (401/403,
1/8, 9, 12, 4/5, 402/404) to the switch board.
9. Install the case wraparound cover.