Sharp R-8320E

TEST PROCEDURE (CONT’D)
PROCEDURE
LETTER
COMPONENT TEST
Q
RELAY UNIT TEST
The relay unit consists of circuits including-relays, buzzer, transformer, etc.
Plug power cord into wall receptacle, the display “88:88” will be flashing.
Remove the outer case and check voltage between pins C-l and C-2 on the relay unit with an A.C.
voltmeter. The meter should indicate 220/240 volts, if not check oven circuit.
If 220/240 volts is indicated but oven components such as the oven lamp, turntable motor, fan
motor, convection motor, damper motor, high voltage components and heating element do not
operate properly.
Set a microwave or convection cooking program and touch cook pad.
1. Oven lamp and turntable motor does not operate.
Check voltage between Pin Nos. C-l and B-2 or B-3 with an A.C. voltmeter.
2201’240 volts A.C. indicated . . . . - . . . . . . . Defective oven components.
220/240 volts A.C. not indicated . . . . . . . . . Defective shut-off relay RY-2.
(Shut-off relay RY-2 does not operate.) . . . .
. (See shut-off relay test or control unit.)
2. Cooling fan motor does not rotate.
Check voltage between pin Nos. C-l and B-4 with an A.C. voltmeter.
220/240 volts A.C. indicated . . . . . . . . . . . . Defective oven components.
220/240 volts A.C. not indicated . . . . . . . . . Defective shut-off relay RY-3.
(Shut-off relay RY-3 does not operate.) . - . .
. (See shut-off relay test or control uinit.)
3. Damper motor does not rotate.
Check voltage between Pin Nos. C-l and B-l with an A.C. voltmeter.
220/240 volts A.C. indicated . . . . . . . . - . . . Defective oven components.
220/240 volts A.C. not indicated . . . . . .
. . . Defective shut-off relay RY-4.
(Shut-off relay RY-4 does not operate.) . . . .
- (See shut-off relay test or control unit.)
4. Convection motor does not rotate.
Check voltage between Pin Nos. C-l and A-2 with an A.C. voltmeter.
220/240 volts A.C. indicated . . . . . . . . . . . . Defective oven components.
220/240 volts A.C. not indicated . . . . . .
. . . Defective shut-off relay RY-1.
(Shut-off relay RY-1 does not operate.) . . . .
. (See shut-off relay test or control unit.)
Shut-off Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the cooking operation (microwave or
convection).
12 volts D.C. indicated . . . . . . . . . . . . . . . . . . Defective shut-off relay
12 volts D.C. not indicated . . . . . . . . . . . .
.
. . . Check the diode which connected to the relay
coil. If diode is good, control unit is defective.
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