Sharp R-501CK Service Manual page 18

R - 5 0 1 C K
R- 501CW
PROCEDURE
LETTER
8. Run the oven and check all functions.
K 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 2 pin connector (A) and the common
terminal of the relay RY1 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,
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.
L COMPU DEFROST TEST
WARNING : The oven should be fully assembled before following procedure.
(1) Place one cup of water in the center of the turntable tray in the oven cavity.
(2) Close the door, touch the " COMPU DEFROST " pad twice.
(3) Touch the Number pad " 5 " and then touch the " START " pad.
(4) The oven is in Compu Defrost cooking condition.
(5) The oven will operate as follows
TEST PROCEDURES
OPERATIONAL VOLTAGE
RY1 Approx. 11.8V D.C.
RY2 Approx. 10.7V D.C.
1ST STAGE
WEIGHT
LEVEL
0.5lb 70%
COMPONENT TEST
control unit is defective.
CONNECTED COMPONENTS
Oven lamp / Turntable motor / Cooling fan motor
Power transformer
2ND STAGE
TIME LEVEL TIME
30sec. 40% 15sec.
16