Daewoo KOG-370A0P Service Manual page 22

( TROUBLE 3 ) No microwave oscillation even though fan motor rotates.
CONDITION
No microwave
oscillation
CHECK
Check continuity of high
voltage fuse
Replace high voltage fuse
Check continuity of high
voltage capacitor
terminals with wires
removed
Check continuity of high
voltage rectifier in
forward and backward
direction with DC
megger
Connect megger leads to
magnetron terminal and
magnetron body
Check resistance of
primary and secondary
coil of high voltage
transformer
Check continuity of
magnetron with wires
removed
Check continuity of
filament terminal of high
voltage transformer
Check D.C. voltage
being supplied to
RELAY (RY1) coil
RESULT
No Continuity
Continuity
high voltage
transformer
Continuity in
backward high voltage
direction
Continuity
magnetron
0 Ω or ¡ Ä
high voltage
transformer
No
Continuity
magnetron
No
Continuity
high voltage
transformer
0 V
touch control
Approx
15 VDC
contacts or
(RY1) or open
21
TROUBLE SHOOTING GUIDE
CAUSE REMEDY
Replace
Defective
Replace
Defective
rectifier
Replace
Defective
Replace
Defective
Replace
Defective
Replace
Defective
Replace
Defective
circuit
Replace
Faulty
RELAY
relay coil