Service manual

ManualsBrandsSharp ManualsDomestic AppliancesR-204

R-204(W)

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

L RELAY TEST

CARRY OUT

3D CHECKS.

Remove the outer case and check voltage between Pin No. 3 of the 2 pin connector (A) and the

common terminal of the relay RY2 on the control unit with an A.C. voltmeter.

The meter should indicate 230 volts, if not check oven circuit.

Relay Test

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. 12.0V D.C. Oven lamp / Turntable motor / Fan motor

RY2 Approx. 11.0V D.C. High voltage transformer

CARRY OUT 4R CHECKS.

M PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING

BOARD(PWB) IS OPEN

To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit

on the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide

given below for repair.

Problem: POWER ON, indicator does not light up.

CARRY OUT 3D CHECKS.

STEPS OCCURRENCE CAUSE OR CORRECTION

1 The rated AC voltage is not present between Check supply voltage and oven power cord.

Pin No, 3 of the 2-pin connector CN-A and

the common terminal of the relay RY2.

2 The rated AC voltage is present at primary Low voltage transformer or secondary circuit defective.

side of low voltage transformer. Check and repair.

3 Only pattern at "a" is broken. *Insert jumper wire J1 and solder.

(CARRY OUT 3D CHECKS BEFORE REPAIR)

4 Pattern at "a" and "b" are broken. *Insert the coil RCILF2003YAZZ between "c" and "d".

(CARRY OUT 3D CHECKS BEFORE REPAIR)

NOTE: *At the time of these repairs, make a

visual inspection of the varistor for

burning damage and examine the

transformer with tester for the pres-

ence of layer short circuit (check pri-

mary coil resistance).

If any abnormal condition is detected,

replace the defective parts.

CARRY OUT 4R CHECKS.

VRS1

RY1

CNA