Sharp R-200BK Service Manual page 16

R-200BK
R-200BW
PROCEDURE
LETTER
J 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. 5 of the 3 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 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 function.
K FOIL PATTERN ON THE PRINTED WIRING BOARD TEST
To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary
on the PWB, this foil pattern acts as a fuse.
1. Foil pattern check and repairs.
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) Follow the troubleshooting guide given below for repair.
STEPS
5) Make a visual inspection of the varistor.
Check for burned damage.
TEST PROCEDURES
control unit is defective.
OPERATIONAL VOLTAGE
RY1 Approx. 17.0V D.C.
The voltage under the condition when all LEDs light up.
OCCURRENCE
1 Only pattern at "a" is broken.
2 Pattern at "a" and "b" are broken.
COMPONENT TEST
CONNECTED COMPONENTS
Oven lamp / Turntable motor / Cooling fan motor /
Power transformer
CAUSE OR CORRECTION
*Insert jumper wire J1 and solder.
*Insert the coil RCILF2003YAZZ between "c" and "d".
c
R11
14
ORG
BRK
5
5
ORG
a
RED
CN-A
RED
b (J1)
d VRS1
,F