LG LRM1250W, Service Manual

Page: 26 / 34

5-15
CONDITION CHECK RESULT CAUSE REMEDY
(TROUBLE 5) No microwave oscillation even though oven lamp and fan motor run.
(Display operates properly)
No microwave
oscillation.
No continuity.
Continuity.
Disconnect the
wire leads from
relay 2 and
check continuity
of relay2.
(Operate the unit)
Defective PCB
assembly
Defective high
voltage
transformer.
Replace PCB
assembly
Output is full power
when you set lower
power level.
Abnormal.
Disconnect the
wire leads from
relay 2 and check
continuity relay 2.
(Operate the unit)
Defective PCB
assembly Replace PCB
assembly
Replace high
voltage
transformer.
Defective high
voltage capacitor.
Replace high
voltage capacitor.
Abnormal
normal
Check high vol-
tage transformer
Abnormal
normal
Check high vol-
tage capacitor.
Defective high
voltage diode.
Replace high
voltage diode.
Abnormal
normal
Check high vol-
tage diode.
Defective
magnetron.
Replace
magnetron.
Abnormal
Check
Magnetron.
NOTE: • Make sure the wire leads correct position.
• When Removing the wire leads from the parts, be sure to grasp the connector, not the wires.
• When removing the magnetron, be sure to install the magnetron gasket in the correct position
and in good condition.