13] procedure l : relay test, 14] procedure m : defrost test, R305ks – Sharp Carousel R-305KS User Manual

Page 19

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R305KS

8 – 6

[13] Procedure L : 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 the normal open terminal of the relay RY1 and the normal open 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.

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.

[14] Procedure M : 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 “DEFROST“ pad once. And then touch the number pad 2.

3. Touch the number pad 5 and then 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.

RELAY SYMBOL

OPERATIONAL VOLTAGE

CONNECTED COMPONENTS

RY1

Approx. -12V D.C.

Oven lamp / Turntable motor / Cooling fan motor

RY2

Approx. -11V D.C.

Power transformer

MENU

1ST STAGE

2ND STAGE

3RD STAGE

Steaks/Chops

LEVEL

TIME

LEVEL

TIME

LEVEL

TIME

0.5lb

70%

17sec.

60%

27sec.

30%

40sec.

G 2

G 1

MINUTE

PLUS

DEFROST

SOFTEN

POWER

LEVEL

REHEAT

WARM

COOK

MELT

POPCORN

TIMER

CLOCK

9

3

6

5

2

8

0

G 3

G 4

G 5

G 6

G 7

G 8

G 9

G10

G11

G12

1

4

7

START

STOP

CLEAR

Pin NO. G12

Pin NO. G1

Key unit ribbon cable

Key unit (Membrane Switch) front view

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