Component Testing; H.v. Transformer - Whirlpool KM-30 8178573 User Manual

Important
Before testing any of the components, perform
the following checks:
• Unplug microwave oven or disconnect power.
• Remove the lead wires from the related com-
ponent before conducting any of the following
tests.
• Discharge the high-voltage capacitor and
remove the lead wires from the primary winding
of the high-voltage transformer before conduct-
ing any of the following tests.
• All operational checks using microwave
energy must be done with the microwave oven
loaded with a minimum of 8 oz (250 mL) of wa-
ter in a microwave safe container.
• Conduct a microwave energy test after per-
forming any tests or repairs to the microwave
oven.
• Check that all wire leads are in the correct
positions before operating the microwave oven.
• Grasp wire connectors when removing the
wire leads from microwave oven parts.
• All testing must be done with an ohmmeter
having a sensitivity of 20,000 ohms per volt DC
or greater, and powered by at least a 9-volt bat-
tery

COmPONENT TESTING

5-1

H.V. TRANSFORmER

1. Unplug microwave oven or disconnect power.
2. Remove wire leads.
3. Measure resistance (ohmmeter scale: Rx1):
• Primary winding: Less than 0.5 ohm (approxi-
mate)
• Secondary winding: 80 ohms (approximate)
• Filament winding: 0 ohms
4. Measure resistance (ohmmeter scale: Rx1k):
• Primary winding to grounding: Normal: Infinite
• Filament winding to grounding: Normal: Infinite
Flament (black & red)
Secondary
(whte wre,
ground to trans-
former case)
Prmary
(termnals)
Red Tube
Black Tube
White
Tube