Sharp R-203BW, Service Manual

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16
R-203BW
R-209BK
R-220BW
(1) Place one cup of water in the center of the turntable tray in the oven cavity.
(2) Close the door, touch the " EXPRESS DEFROST " pad once.
(3) The oven is in Express Defrost cooking condition.
(4) The oven will operate as follows.
WEIGHT 1ST STAGE 2ND STAGE 3RD STAGE 4TH STAGE
LEVEL TIME LEVEL TIME LEVEL TIME LEVEL TIME
0.5lb 70% 1min.2sec. 0% 1min.2sec. 50% 32sec. 30% 50sec.
(5) If improper operation is indicated, the control unit is probably defective and should be checked.
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT 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. 3 of the 2 pin connector (A) and the
common terminal of the relay RY2 on the control unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
RY1 and RY2 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.
DC. voltage indicated ............. Defective relay.
DC. voltage not indicated ........ Check diode which is connected to the relay coil. If diode is good,
control unit is defective.
RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 Approx. 15.0V D.C. Oven lamp / Turntable motor / Cooling fan motor
RY2 Approx. 14.0V D.C. Power transformer
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 function.
K RELAY TEST
L EXPRESS DEFROST TEST
1
2
3
4 5
6
7
8 9
0
POPCORN
START
POWER
LEVEL
STOP
CLEAR
MINUTE
PLUS
BEVERAGE
FRESH
VEGETABLES
EXPRESS
DEFROST
DINNER
PLATE
BAKED
POTATO
TIMER
CLOCK
ROLL,
MUFFIN
G 6 G 5 G 4 G 3 G 2 G 1
G 7
G 8
G 9
G10