Daewoo KOC-960P0A Service Manual page 32

(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 heater
with wires removed
Check continuity of
filament terminal of
high voltage
transformer
Check continuity of
microwave select
switch
Check D.C. voltage
being supplied to
RELAY (RY6) coil
Result
No
Continuity
Defective high
Continuity
voltage transformer
Defective high
Continuity
voltage rectifier
in backward
direction
Defective
Continuity
magnetron
0 Ω or ∞
Defective high
voltage transformer
Defective
No
magnetron
Continuity
No Defective high
voltage transformer
Continuity
Defective timer
No
ass'y
Continuity
Defective touch
0V
control circuit
Faulty contacts or
Approx.
RELAY (RY6) or
15VDC
open relay coil
35
Cause Remedy
Replace
Replace
Replace
Replace
Replace
Replace
Replace
Replace
Replace