Relay Test - Sharp R-820BK Service Manual

PROCEDURE
LETTER
If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the
control unit does not respond, it is faulty and must be replaced. If a specific pad does not respond,
the above method may be used (after clearing the control unit) to determine if the control unit or key
pad is at fault.
5. Reconnect all leads removed from components during testing.
6. Re-install the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
N

RELAY TEST

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 these leads remain isolated from other components and oven chassis by using insulation
tape.
6. After that procedure, re-connect the power supply cord.
7. Remove the outer case and check voltage between Pin No. 1 of the 3 pin connector (A) and the
common terminal of the relay RY6 on the control unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
Shut off, Cook and Heater Relay Test
These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill
cooking operation, or convection cooking operation.
DC. voltage indicated ............. Defective relay.
DC. voltage not indicated ........ Check diode which is connected to the relay coil. If diode is good, control
RELAY SYMBOL
8. Disconnect the power supply cord, and then remove outer case.
9. Open the door and block it open.
10.Discharge high voltage capacitor.
11.Reconnect all leads removed from components during testing.
12.Re-install the outer case (cabinet).
13.Reconnect the power supply cord after the outer case is installed.
14.Run the oven and check all functions.
TEST PROCEDURES
G 8 G 7
5
4
0 9
START
POWER
ROAST REHEAT
LEVEL
TOUCH ON
MINUTE
CLOCK
PLUS
unit is defective.
OPERATIONAL VOLTAGE
RY1 Approx. 24.0V D.C.
RY2 Approx. 24.0V D.C.
RY3 Approx. 24.0V D.C.
RY4 Approx. 24.0V D.C.
RY5 Approx. 24.0V D.C.
RY6 Approx. 24.0V D.C.
COMPONENT TEST
G 6 G 5 G 4 G 3
2 1
3
GRILL
PIZZA
8 7 6
ROAST GRILL
DEFROST KITCHEN
TIMER
CONNECTED COMPONENTS
Convection motor
Power transformer
Grill heaters (Top)
Bottom heater
Fan motor
Oven lamp / Turntable motor
21
G 2 G 1
CUSTOM
BAKE
HELP
STOP
COOK
CLEAR
CONVEC
POPCORN
R-820BK
R-820BW