Sharp R-530EK-T, Service Manual

Page: 19 / 44

R530EWT
8 – 6
7. Remove the outer case and check voltage between the cabinet side terminal of the relay RY1 and Pin No. 1 of 2 pin connector (A) 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.
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.
[13] M: DEFROST CENTER TEST
WARNING: The oven should be fully assembled before following procedure.
1. Open the door.
2. Place one cup of water in the center of the turntable tray in the oven cavity.
3. Close the door, touch the Defrost Center pad and touch the number pad 5. And touch the number pad 5 again. And touch the Start pad.
4. The oven is in Defrost cooking condition.
5. The oven will operate as follows.
6. If improper operation is indicated, the control unit is probably defective and should be checked.
[14] N: 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.
5) Make a visual inspection of the varistor. Check for burned damage and examine the trans-
former with a tester for the presence of layer short-circuit (check the primary coil resistance
which is approximately 210
Ω±
15%). If any abnormal condition is detected, replace the con-
trol unit.
6) Reconnect all leads removed from components during testing.
7) Re-install the outer case (cabinet).
8) Reconnect the power supply cord after the outer case is installed.
9) Run the oven and check all functions.
2. Follow the troubleshooting guide given below, if indicator does not light up after above
check and repairs are finished.
1) Disconnect the power supply cord and then remove outer case.
2) Open the door and block it open.
RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 Approx. 24.0V D.C. Oven lamp / Turntable motor / Cooling fan motor
RY2 Approx. 23.0V D.C. Power transformer
MENU 1ST STAGE 2ND STAGE
Steaks/Chops or Fish LEVEL TIME LEVEL TIME
0.5lb 70% 30sec. 40% 15sec.
STEPS OCCURRENCE CAUSE OR CORRECTION
1 Only pattern at “a” is broken. *Insert jumper wire J1 and solder.
2 Pattern at “a” and “b” are broken. Replace the control unit.
T1
AC
VRS1
OMIF DU
CN - A
(J1)
a
b
c
d
12
XA
VH