MICROWAVE OVEN
Troubleshooting & Technical Data
6-6
PROCEDURE
LETTER
COMPONENT TEST
TEST PROCEDURES
F
G
SECONDARY INTERLOCK SWITCH TEST
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open door and block it open.
3.
Discharge high-voltage capacitor.
4.
Isolate the switch and connect the ohmmeter to the common (COM) and normally open (NO) terminal of the
switch. The meter should indicate an open circuit with the door open and a closed circuit with the door
closed. If improper operation is indicated, replace the the complete Latch Hook/Switch Assembly.
5.
Reconnect all leads removed from components during testing.
6.
Reinstall the outer cabinet case, then reconnect power supply cord.
7.
Run the oven and check all functions.
PRIMARY INTERLOCK SYSTEM TEST
DOOR SENSING SWITCH
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open door and block it open.
3.
Discharge high-voltage capacitor.
4.
Isolate the switch and connect the ohmmeter to the common (COM) and normally open (NO) terminal of the
switch. The meter should indicate an open circuit with the door open and a closed circuit with the door
closed. If improper operation is indicated, replace the the complete Latch Hook/Switch Assembly.
5.
Reconnect all leads removed from components during testing.
6.
Reinstall the outer cabinet case, then reconnect power supply cord.
7.
Run the oven and check all functions.
NOTE
:
If the door sensing switch contacts fail in the open position and the door is closed, the cooling fan,
turntable and oven light will be activated by RY1.
PRIMARY INTERLOCK RELAY (RY2)
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open door and block it open.
3.
Discharge high-voltage capacitor.
4.
Disconnect wire leads from the male tab terminals of Primary Interlock Relay. Check the state of the relay
contacts with an ohmmeter, contacts should be open. If contacts are closed, replace entire circuit board.
5.
Reconnect all leads removed from components during testing.
6.
Reinstall the outer cabinet case, then reconnect power supply cord.
7.
Run the oven and check all functions.
MONITOR SWITCH TEST
1.
Disconnect power supply cord and remove outer cabinet case.
2.
Open door and block it open.
3.
Discharge high-voltage capacitor.
4.
Before performing this test, make sure secondary interlock switch and primary interlock relay are operating
properly. Then, disconnect wire lead from monitor switch (COM) terminal. Check monitor switch operation
with ohmmeter as follows: With door open, meter should indicate a closed circuit. With monitor switch
actuator pushed by a screw driver through the lower latch hole in oven cavity face plate and door opened
(in this condition, monitor switch plunger is pushed in), meter should indicate an open circuit. If proper oper-
ation is indicated, reconnect wire lead to the monitor switch (COM) terminal and check continuity of monitor
circuit. If monitor switch or monitor circuit indicates improper operation, replace Latch Hook/Switch
Assembly.
5.
Reconnect all leads removed from
components during testing.
6.
Reinstall the outer cabinet case,
then reconnect power supply cord.
7.
Run the oven and check all func-
tions.
P
P
P
P
rr
rr
ii
ii
o
o
o
o
rr
rr
tt
tt
o
o
o
o
S
S
S
S
e
e
e
e
rr
rr
ii
ii
a
a
a
a
ll
ll
N
N
N
N
u
u
u
u
m
m
m
m
b
b
b
b
e
e
e
e
rr
rr
1
1
1
1
2
2
2
2
0
0
0
0
0
0
0
0
1
1
1
1
5
5
5
5
4
4
4
4
Monitor
Switch
Secondary Interlock Switch
Screw Driver
Ohmmeter
RED
WHT/WHT
