R-20A1(S)VN
7 – 1
R218L(W)
CHAPTER 7.
TROUBLESHOOTING GUIDE
[1] FOREWORD
When troubleshooting the microwave oven, it is helpful to follow the
Sequence of Operation in performing the checks. Many of the possible
tests are given a procedure letter which will be found in the “Test Pro-
cedure” section.
IMPORTANT:
If the oven becomes inoper ative because of a blown fuse T6.3A in the
monitored latch switch - relay RY1 - timer switch - monitor switch cir-
cuit, check the monitored latch switch, relay RY1, timer switch and
monitor switch before replacing the fuse T6.3A.
[2] CHART
MAGNETRON
HIGH
VOLTAGE
T
RANSFORMER
H.V.
RECTIFIER
ASSEMBLY
HIGH
VOLTAGE
WIRE
HIGH
VOLTAGE
C
APACITOR
MONITORED.
LATCH
SWITCH
LACTCH
SWITCH
TEMPERATURE
F
USE
MONITOR
SWITCH
TIMER
MOTOR
TIMER
SWITCH
FAN
M
OTOR
TURNTABLE
M
OTOR
FUSE
T6.3A
RELAY
(RY-1)
FOIL
PATERN
O
N
P
.W.B.
POWER
S
UPPLY
C
ORD
SHORTED
WIRE
H
ARNESS
OPENED
WIRE
H
ARNESS
OVEN
LAMP
WALL
OUTLET
MISADJUSTMENT
S
WITCH
HOME
FUSE
OR
BREAKER
BLOCKED
COOLING
F
AN
BLOCKED
VENTILATION
H.V.
FUSE
OFF
CONDITION
PROBLEM
CONDITION
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
TEST PROCEDURE
ON
CONDITION
A B C
CK
D
E
E
I
J
F
E
M
H
G
G
J
L
RE CK CK RE CK CK CK CK CK
Home fuse blows when pow-
ersupply cord is plugged into
wall outlet.
FUSE T6.3A blows when
power supply cord is plug-
ged into wall outlet.
Oven does not start when
the timer is set
Oven lamp does not light
(Other function is normal.)
Fan motor does not operate.
(Other function is normal.)
Turntable motor does not
operate. (Other function is
normal.)
Oven or any electrical parts
does not stop.
Oven seems to be operating
but little or no heat is pro-
duced in oven load. (Micro-
wave power level is set at
HIGH)
Oven does not seems to be
operating properly when
MED HIGH, MED, MED
LOW or LOW is set. (Oven
operates properly at HIGH.)
Oven goes into cook cycle
but shuts down before end
of cooking cycle.
