7-25
(TROUBLE 2) Microwave oven does not operate at all, Display window does not display any figures,
and no input is accepted.
CONDITION
CHECK
RESULT
CAUSE
REMEDY
2. Fuse does not
blow.
No continuity.
Continuity.
Check continuity
of power supply
cord.
Defective power
supply cord.
Replace power
supply cord.
Defective
thermostat.
Replace
thermostat.
Check continuity
of magnetron
thermostat.
No continuity.
1. Fuse blows.
Continuity.
Malfunction of the
monitor switch.
Replace fuse,
primary, monitor
switches, and
RELAY(RY8) of
P.C.B Assembly.
Check continuity
of monitor
switch (with
door closed).
Check continuity
of primary
switch (with
door opened).
No continuity.
Disconnect one
side of the wire
lead connected
from transformer
to the high
voltage
capacitor and
operate the unit.
No continuity.
Continuity.
Shorted contact at
the primary switch.
Replace fuse,
primary, monitor
switches, and
RELAY(RY8) of
P.C.B Assembly.
Fuse blows again
Normal.
Defective high
voltage capacitor.
Replace high
voltage capacitor.
Defective high volt-
age transformer.
Replace high volt-
age transformer.
Replace fuse
