Service manual

23
(TROUBLE 3) No microwave oscillation even though fan motor rotates.
TROUBLE SHOOTING GUIDE
CONDITION
CHECK RESULT
Continuit
y
Continuity in
backwar
d
direction
0 Ω Or infnity
No
Continuity
No
Continuity
0 V
Appro
x
15 VDC
CAUSE
Defective
high voltag
transformer
Defective
high voltag
rectifier
Defectiv
e
magnetron
Defective
magnetron
Defective
high voltag
transformer
Defectiv
e
high voltage
transformer
Defective
touch control
circuit
Faulty
contacts o
f
RELAY
(RY1) or open
relay coil
REMED
Y
Replace
Replace
Replace
Replace
Replace
Replace
Replace
Replace
No microwave
oscillation
Check continuity of high
voltage rectifier i
n
forward and backward
direction with DC
megger
Check continuity of high
voltage capacitor
terminals with wires
removed
Connect megger leads to
magnetron terminal and
magnetron bod
y
Check resistance of
primary and secondary
coil of high voltage
transformer
Check continuity of
magnetron with wires
remove
d
Check continuity of
filament terminal of hig
h
voltage transformer
Check D.C. voltage
being supplied to
RELAY (RY1) coil
Continuit
y