Service manual

7
R-1512
R-1511
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. VARIABLE COOKING CONTROL "HIGH".
4. "START" BUTTON PRESSED.
Figure O-2. Oven Schematic-Cooking Condition
MAGNETRON
TEMPERATURE FUSE
FUSE
20A
TURNTABLE MOTOR
FAN MOTOR
MAGNETRON
OVEN LAMP
MONITOR SWITCH
BLKWHT
POWER
TRANSFORMER
HIGH VOLTAGE
CAPACITOR
0.94∝F/ AC2300V
HIGH VOLTAGE
RECTIFIER
COM.
N.O.
COM.
CONTROL UNIT
GND
GRN
HOOD
MOTOR
A5
B5
B7
B9
Low
High
A1 A3 B1 B3
N.O.
E1
E2
DOOR
SENSING
SWITCH
PRIMARY
INTERLOCK
SWITCH
120 V AC.
60 Hz
HOOD
LAMP
HL
RY1
RY2
SECONDARY
INTERLOCK
RELAY
OVEN LAMP
RELAY
FM
OL
TTM
HOOD FAN
THERMAL
CUT OUT
HOOD
CAPACITOR
RY4
RY6
RY5
RY3
N.C.
CAVITY
THERMAL CUT-OUT
HL
F1
F2
F3
AH SENSOR
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 moni-
tor fuse, check the monitor switch, relay (RY1) secondary
interlock relay (RY2), door sensing switch and primary
interlock switch before replacing the monitor fuse. If monitor
fuse is replaced, the monitor switch must also be replaced.
Use part FFS-BA016/KiT as an assembly.
IMPORTANT:
Whenever troubleshooting is performed with the power
supply cord disconnected. It may in, some cases, be neces-
sary 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.