Lincoln Electric INVERTEC STT Series Service Manual page 73

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Apply Positive Apply Negative
Test Probe to Test Probe to
Terminal Terminal
1/8 12
12 1/8
9 4/5
4/5 9
1/8 9
9 1/8
12 4/5
4/5 12
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).
TROUBLESHOOTING & REPAIR
SWITCH BOARD TEST (continued)
TABLE F.5 – SWITCH BOARD RESISTANCE TEST
Test Result Conclusion Repair Action
Greater than OK
1K ohm
Less than Shorted
100 ohms
Less than OK
100 ohms
Greater than Open
1K ohm
Greater than OK
1K ohm
Less than Shorted
100 ohms
Less than OK
100 ohms
Greater than Open
1K ohm
Less than OK
100 ohms
Greater than Open
1K ohm
Greater than OK
1K ohm
Less than Shorted
100 ohms
Less than OK
100 ohms
Greater than Open
1K ohm
Greater than OK
1K ohm
Less than Shorted
100 ohms
Continued . . .
INVERTEC STT
Next Procedure Notes
None Continue
Replace both Snubber Test
switch boards
None Continue
Replace both Snubber Test
switch boards
None Continue
Replace both Snubber Test
switch boards
None Continue
Replace both Snubber Test
switch boards
None Continue
Replace both Snubber Test
switch boards
None Continue
Replace both Snubber Test
switch boards
None Continue
Replace both Snubber Test
switch boards
None Continue
Replace both Snubber Test
switch boards
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