Daewoo KOR664BWTAE013AB00 Service Manual page 19

(TROUBLE 3) No microwave oscillation even though fan motor rotates.
CONDITION
No
microwave
oscillation
Check continuity of high voltage
rectifier in forward and backward
Check resistance of primary and
CHECK
Check continuity of high
voltage capacitor terminals
with wires removed
direction with DC megger
Connect megger leads to
magnetron terminal and
magnetron body
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
Continuity
Continuity in
backward
voltage rectifier
direction
Continuity
0 Ω or ∞
No
Continuity
No
Continuity
0 V
Defective touch
Approx
11 VDC
18
CAUSE REMEDY
Defective high
voltage
transformer
Defective high
Defective
magnetron
Defective high
voltage
transformer
Defective
magnetron
Defective high
voltage
transformer
control circuit
Faulty
contacts or
RELAY (RY1)
or open
relay coil
Replace
Replace
Replace
Replace
Replace
Replace
Replace
Replace