GE ZEK957 Series Technical Service Manual page 45

Microwave Unit Dead
YES
Perform Monitor
Switch Test.
Pass test?
YES
Visually inspect
varistor.
Varistor OK?
YES
Perform High-
Voltage
Transformer Test.
Pass test?
YES
Perform High-
Voltage Capacitor
Test.
Pass test?
YES
Perform
Magnetron Test.
Pass test?
YES
System checks
normal. Replace
fuse.
Check fuse.
Is fuse blown?
NO Replace monitor.
NO Replace PCB.
Replace high-
NO voltage
transformer.
Replace high-
NO
voltage capacitor.
Replace
NO
magnetron.
NO
Check:
120 VAC
Magnetron TCO
Flame TCO
All OK?
YES
Check for continuity:
Black wire - line-in to
RY2.
White wire - CON02
connector to neutral.
Continuity OK?
YES
Replace PBC.
– 43 –
Repair or replace
NO
faulty component.
NO Repair circuit.