Sharp R-9380

R-9380
TEST PROCEDURES (CONT’D)
PROCEDURE
LETTER
COMPONENT TEST
F
TEMP. FUSE TEST
A continuity check across the temp. fuse terminals should indicate a closed circuit unless the
temperature of the temp. fuse reaches approximately 115 “C.
An open magnetron temp. fuse indicates overheating of the magnetron assembly. If the temp.
fuse indicates a open circuit, replace the temp. fuse and check for restricted air flow to the
magnetron through the opening in the chassis, especially the air duct and fan motor.
G
MONITOR SWITCH TEST
Desconnect oven from power supply cord. Before performing this test, make sure that the upper
latch switch and lower latch switch are operating properly referring to the above Switch Test
Procedure.
Disconnect the wire lead from the upper latch switch (NO) terminal.
Check the monitor switch operation by using the ohmmeter as follows.
When the door is open, the meter should indicate a closed circuit.
When the monitor switch actuater is pushed by a screw driver through the lower latch hole on
the front plate of the oven cavity with the door opened (in this condition the plunger of the
monitor switch is pushed in), the meter should indicate an open circuit.
If improper operation is indicated, the switch may be defective.
After testing the monitor switch, re-connect the wire lead to the upper latch switch (NO) termi-
nal.
POWER TRANSFORMER
OHMMETER
MONITOR
SWITCH
H BLOWN OVEN FUSE
If the oven fuse in the upper latch switch-monitor switch circuit is blown when the door is
opened, check the upper latch switch and monitor switch before replacing the blown fuse.
If the oven fuse is blown by improper switch operation, replace the defective switch and oven
fuse at the same time.
Replace just the oven fuse if the switches operate normally.
CAUTION; REPLACEMENT FUSE MUST BE THE LISTED FUSE IN PARTS LIST.
I
THERMAL CUT-OUT TEST
A continuity check across the thermal cut-out terminals should indicate a closed circuit. If the
temperature of the steam duct reaches approximately 115 “C the thermal cut-out opens.
The termal cut-out resets automatically at below -20 “C.
An open thermal cut-out indicates overheating of the oven cavity. Check for restricted air flow
to the magnetron through the opening in the chassis, especially the cooling duct and fan.
CAUTION; IF THE THERMAL CUT-OUT INDICATES OPEN CIRCUIT, REPLACE THE THER-
MAL CUT-OUT.
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