F-68
FIELD EFFECT TRANSISTOR/SWITCH BOARD TEST (continued)
TABLE F.3 – SWITCH BOARD 2 RESISTANCE TEST TABLE (Continued)
Apply
Positive
Test
Probe to
Terminal
12B
1B
12B
403
9B
404
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
Apply
Negative
Test
Probe to
Test
Terminal
Result
1B
Less than
100 ohms
Greater
than 1K
ohm
12B
Greater
than 1K
ohm
Less than
100 ohms
403
Greater
than 1K
ohm
Less than
100 ohms
12B
Less than
100 ohms
Greater
than 1K
ohm
404
Less than
100 ohms
Greater
than 1K
ohm
9B
Greater
than 1K
ohm
Less than
100 ohms
POWER WAVE 450
Repair
Conclusion
Action
OK
None
Open
Replace 4
Switch
Boards
OK
None
Shorted
Replace 4
Switch
Boards
OK
None
Shorted
Replace 4
Switch
Boards
OK
None
Open
Replace 4
Switch
Boards
OK
None
Open
Replace 4
Switch
Boards
OK
None
Shorted
Replace 4
Switch
boards
F-68
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