R-21JCA-F
9
TROUBLESHOOTING GUIDE
Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.
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 monitor fuse, check the monitor switch, primary interlock relay
(RY1), door sensing switch and secondary interlock switch before replacing the monitor fuse. If monitor fuse is
replaced, the monitor switch must also be replaced. Use part FFS-BA015WRK0 as an assembly.
IMPORTANT: Whenever troubleshooting is performed with the power supply cord disconnected. It may in, some cases, be
necessary to connect the power supply cord after the outer case has been removed, in this event,
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. Disconnect the leads to the primary of the power transformer.
5. Ensure that the leads remain isolated from other components and oven chassis by using insulation tape.
6. After that procedure, reconnect the power supply cord.
When the testing is completed
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. Reconnect the leads to the primary of the power transformer.
5. Reinstall the outer case (cabinet).
6. Reconnect the power supply cord after the outer case is installed.
7. Run the oven and check all functions.
TEST PROCEDURE
CONDITION PROBLEM
POSSIBLE CASE
AND
DEFECTIVE PARTS
Home fuse or circuit breaker blows when
power cord is plugged into wall outlet.
Monitor fuse blows when power cord is
plugged into wall outlet.
Oven lamp does not light, and fan motor
and antenna motor do not operate.
Oven does not go into cook cycle when
Light Up Dial turned.
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 produced in
oven load (food).
OFF
CONDITION
COOKING
CONDITION
MAGNETRON
POWER TRANSFORMER
H.V. RECTIFIER ASSEMBLY
HIGH VOLTAGE CAPACITOR
THERMAL CUT-OUT
SECONDARY INTERLOCK SWITCH
PRIMARY INTERLOCK SYSTEM
MONITOR SWITCH
MONITOR FUSE
NOISE FILTER
CONTROL PANEL
RELAY (RY2)
FOIL PATTURN ON P.W.B.
LOW VOLTAGE
WRONG OPERATION
DIRTY OVEN CAVITY
SHORTED IN POWER CORD
OVEN LAMP OR SOCKET
COOLING FAN MOTOR
ANTENNA MOTOR
SHORT OR OPENED WIRING
ABCDEFFGHI JKL
RE RE RE RE RE
CK CK CK
