Sharp R-21JCA-F Test Procedures Procedure, Letter, Component Test, K Relay Test, Relay Symbol

R-21JCA-F

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

6)After that procedure, re-connect the power supply cord.

1.Control Panel

The following symptoms indicate a defective control unit.

1-1 In connection with LEDs

a)At a certain LED, all or some LEDs do not light up.

b)At a certain LED, brightness is low.

c)Only one LED does not light up.

d)All or some LEDs continue to light up.

e)A certain group of LEDs do not light up.

f)The LEDs flicker.

1-2 Other possible troubles caused by defective control unit.

a)Buzzer does not sound or continues to sound.

b)Clock is not possible.

c)Cooking time can not be set.

When testing is completed,

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)Reconnect all leads removed from components during testing.

5)Re-install the outer case (cabinet).

6)Reconnect the power supply cord after the outer case is installed.

7)Run the oven and check all functions.

KRELAY 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 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. 19.2V D.C.		Oven lamp / Antenna motor / Cooling fan motor
RY2	Approx. 19.9V D.C.		Power transformer

The voltage under the condition when all LEDs light up.

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.

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