Service manual
10
R-204EWA
A MAGNETRON ASSEMBLY TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check
across the magnetron filament leads should indicate less than 1 ohm.
CK = Check / RE = Replace
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
RE CK AB C
D
EF FGHRE RE CK
I/K
CK CK CK J M L
SHORT IN POWER CORD
SHORT OR OPEN WIRING
MAGNETRON
POWER TRANSFORMER
H.V. RECTIFIER ASSEMBLY
HIGH VOLTAGE CAPACITOR
MAGNETRON THERMAL CUT-OUT
PRIMARY INTERLOCK SYSTEM
SECONDARY INTERLOCK SWITCH
MONITOR SWITCH
C/T FUSE
OVEN LAMP OR SOCKET
COOLING FAN MOTOR
TURNTABLE MOTOR
CONTROL UNIT OR RELAY
WRONG OPERATION
LOW VOLTAGE
DIRTY OVEN CAVITY
KEY UNIT
FOIL PATTERN ON PWB.
EXPRESS DEFROST/ COMPU DEFROST
Home fuse blows when power cord
is plugged into wall receptacle.
C/T fuse blows when power cord is
plugged into wall receptacle.
Any letters or indicators do not ap-
pear in display when power cord is
first plugged into wall outlet.
Display does not operate properly
when STOP/CLEAR key is touched.
(Buzzer should sound and time of
day should appear in display.)
C/T fuse blows when the door is
opened.
Fan motor does not operate. (All
other electric components function.)
Oven lamp does not light at all. (All
other electric components function.)
Turntable motor does not operate. (All
other electric components function.)
Oven does not go into cook cycle
when START pad is touched
Oven seems to be operating but little
or no heat is produced in oven load.
(Food incompletely cooked or not
cooked at all at end of cook cycle.)
Oven goes into a cook cycle but
extremely uneven heating is pro-
duced in oven load (food).
Oven does not cook properly when
programmed for Cooking Power 50%
mode. (Operates properly on Cook-
ing Power 100% mode.)
Oven lamp, turntable motor and fan
motor do not operate.
Oven goes into EXPRESS DE-
FROST/COMPU DEFROST but food
is not defrosted well.
TEST PROCEDURE
PROBLEM
CONDITION
OFF
CONDITION
COOKING
CONDITION
POSSIBLE CAUSE
AND
DEFECTIVE PARTS