Daewoo KOR-6QAB5S, Service Manual

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19
(TROUBLE 3) No microwave oscillation even though fan motor rotates.
Condition
No
microwave
oscillation
Check Result Cause Remedy
Replace Check continuity
of high voltage
capacitor
terminals with
wires removed Continuity Defective high
voltage
transformer
Replace Check continuity of
high voltage diode
in forward and
backward direction
with DC megger Continuity in
backward
diode Defective high
voltage diode
Replace Connect megger
leads to
magnetron
terminal and
magnetron body Continuity Defective
magnetron
Replace Check resistance
of primary and
secondary coil of
high voltage
transformer Defective high
voltage
transformer
Replace Check continuity
of magnetron
with wires
removed No
Continuity Defective
magnetron
Replace Check continuity
of filament
terminal of high
voltage
transformer No
Continuity Defective high
voltage
transformer
Replace Check D.C.
voltage being
supplied to
RELAY (RY1)
coil 0V Defective touch
control circuit
Replace Approx
15 VDC Faulty contacts of
RELAY (RY1) or
open relay coil
19