R-27STM
7
MAGNETRON
HIGH VOLTAGE TRANSFORMER
H.V. RECTIFIER ASSEMBLY
HIGH VOLTAGE WIRE
HIGH VOLTAGE CAPACITOR
1ST. LATCH SWITCH
2ND. INTERLOCK RELAY CONTROL
SWITCH
MONITOR SWITCH
T
E
M
P
E
R
A
T
U
R
E
F
U
S
E
1
5
0
ºC
(
O
V
E
N
)
FAN MOTOR
TURNTABLE MOTOR
FUSE T6.3A
TOUCH CONTROL PANEL
RELAY (RY-1)
RELAY (RY-2)
FOIL PATERN ON P.W.B.
POWER SUPPLY CORD
SHORTED WIRE HARNESS
OPENED WIRE HARNESS
OVEN LAMP
WALL OUTLET
MISADJUSTMENT SWITCH
HOME FUSE OR BREAKER
BLOCKED COOLING FAN
BLOCKED VENTILATION
NOISE FILTER
SWITCH UNIT
H.V. FUSE
OFF
CONDITION
PROBLEM
CONDITION
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
TEST PROCEDURE
ON
CONDITION
A B C
CK
D
E
E
E F G G H K
M N
I L J
M
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.
"88:88" does not appear in
display but power supply cord
is plugged into wall outlet.
Display does not operate
properly when STOP/CLEAR
button is pressed.
Oven does not start when the
START button is touched.
(Display appears)
Oven lamp does not light
(Display appears.)
Fan motor does not operate.
(Display appears.)
Turntable motor does not
operate. (Display appears.)
Oven or any electrical parts
does not stop when cooking
time is 0 or STOP button is
pressed.
Oven seems to be operating
but little or no heat is pro-
duced in oven load. (Micro-
wave power level is set at
100%)
Oven does not seems to be
operating properly when
70%,50%, 30% or 10% is
set. (Oven operates properly
at 100%.)
Oven goes into cook cycle
but shuts down before end
of cooking cycle.
TROUBLESHOOTING GUIDE
FOREWORD
When troubleshooting the microwave oven, it is helpful to follow
the Sequence of Operation in performing the checks. Many of
the possible causes of trouble will require that a specific test be
performed. These tests are given a procedure letter which will
be found in the "Test Procedure" section.
IMPORTANT:
If the oven becomes inoperative because of a blown fuse T6.3A
in the 1st. latch switch - relay (RY1) - 2nd. interlock relay (RY2)-
monitor switch circuit, check the 1st. latch switch, relay (RY1),
2nd. interlock relay (RY2) and monitor switch before replacing
the fuse T6.3A.
R27STM.indd 7
11/3/08 2:04:26 PM
