Sharp R-1481 ユーザーズマニュアル

19

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. 7 of the 4 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, control unit is defective.

RELAY SYMBOL

OPERATIONAL VOLTAGE

CONNECTED COMPONENTS

RY1

Approx. 24.0V D.C.

Oven lamp / Fan motor / Stirrer motor

RY2(COOK)

Approx. 24.0V D.C.

Power transformer

RY3

Approx. 24.0V D.C.

Turntable motor

RY4

Approx. 24.0V D.C.

Hood motor

RY5

Approx. 24.0V D.C.

Hood motor (HIGH /LOW selection)

  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.

(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 once and touch the Number pad "1" and touch

the Number pad "5". And then touch the "START" pad.

(3) The oven is in Compu 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

0.5lbs

70%

35sec.

0%

40sec.

50%

30sec.

30%

35sec.

(5) If improper operation is indicated, the control unit is probably defective and should be checked.

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.