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R362M - 5

MICROWAVE OUTPUT POWER (IEC-705)

The power output of this oven is rated using the method specified by IEC-705.  Full details of how to carry out this
procedure can be found in the Sharp Technical Training notes which is available from Sharp Parts Centre
(part number SERV-LITMW01).

Using this procedure, the heating time to raise 1000g of water by 10

°

C is approximately 50 seconds.

The IEC-705 procedure must be carried out using laboratory-type procedures and equipment.  These requirements
make the procedure unsuitable for routing performance checks.  An indication of the power being produced by the oven
can however be obtained using the procedure given below.

Alternative simplified method:
1. Place 2 litres of cold water (between 12

°

C and 20

°

C) in a suitable container.

2. Stir the water and measure the temperature in 

°

C.  Note temperature as T1.

3. Place the container in the microwave and heat the water for 2 minutes on full power.
4. When the 2 minutes is completed, remove the container and stir the water.  Note the water temperature as T2.
5. Calculate the output power using the following formula:

R.F. Power Output = (T2 - T1) x 80.

MICROWAVE LEAKAGE TEST

This oven should be tested for microwave leakage on completion of any repair or adjustment, following the procedure
described in the Sharp Technical Training notes (part number SERV-LITMW01).  The maximum leakage permitted in
BS EN 60335-2-25 is 50W/m

2 

(equivalent to 5mW/cm

2

), however it is not normal to detect any significant leakage,

therefore, any leakage which is detected should be investigated.

It is essential that only leakage detectors with current calibration traceable to the National Physical Laboratories are used.

Suitable leakage detectors :

CELTEC A100
APOLLO X1

R362M - 6

If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon
cable is marking good contact, verify that the door sensing switch (stop switch) operates
properly; that is the contacts are closed when the door is closed and open when the door is
open. If the door sensing switch (stop switch) is good, disconnect the flat ribbon cable that
connects the key unit to the control unit and make sure the door sensing switch is closed
(either close the door or short the door sensing switch connecter). Use the Key unit matrix
indicated on the control panel schematic and place a jumper wire between the pins that
correspond to the STOP/CLEAR pad marking momentary contact. If the control unit responds
by clearing with a beep the key unit is faulty and must be replaced. If the control unit does not
respond, it is faulty and must be replaced.  If a specific pad does not respond, the above
method may be used (after clearing the control unit) to determine if the control unit or key pad
is at fault.

CARRY OUT 4R CHECKS.

The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore,
unlike conventional microwave ovens, proper maintenance can not be performed with only a voltmeter
and ohmmeter.
In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key
Unit, and also the Control unit is divided into two units, CPU unit and Power unit, and troubleshooting
by replacement is described according to the symptoms indicated.
1.  Key Unit   Note : Check key unit ribbon connection before replacement.

The following symptoms indicate a defective key unit. Replace the key unit.

a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.

2. Control Panel

The following symptoms indicate a defective control unit. Before replacing the control unit.
perform the key unit test (Procedure K) to determine if control unit is faulty.

2-1  In connection with pads

a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.

2-2  In connection with indicators

a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light up.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.

2-3  Other possible troubles caused by defective control unit.

a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
d) Proper temperature measurement is not obtained.

G 8

G 7

G 6

G 5

G 4

G 3

G 2

G 1

G12

G11

G10

G 9

MORE

START

CLOCK

AUTO

MINUTE

AUTO

START

AUTO

DEFROST

AUTO

COOK

STOP/

CLEAR

POWER

LEVEL

Kg / L b

g • oz

Kg • Lb

10 sec.

1 min.

10 min.

info

TIMER

LESS

CHILLED MEALS

FRESH FISH

RICE/PASTA

SPONGE PUDDING

PORRIDGE

FROZEN MEALS JACKET POTATOES

FRESH VEG.

CANNED FOOD

R362M - 7

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

visual inspection of the varistor for burn-
ing damage and examine the trans-
former with tester for the presence of
layer short circuit (check primary coil
resistance).
If any abnormal condition is detected,
replace the defective parts.

CARRY OUT 4R CHECKS.

CARRY OUT 3D CHECKS.

Remove the outer case and check voltage between Pin Nos. 1 and 3 of the 4 pin connector (E) on
the control unit with an A.C. voltmeter.
The meter should indicate 230-240 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

RY2

Approx. 18.0V D.C.

High voltage transformer

RY5

Approx. 24.0V D.C.

Fan motor / Turntable motor / Oven lamp

CARRY OUT 4R CHECKS.

(J1)

9

8

C2

VRS1

RY3

5 FAN

AC 1 - 5

     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 Nos. 1 and 3 of the 4-pin connector (E).

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.)

R362M - 8

(1) The oven should be plugged in at least two minutes before sensor cooking.
(2) Room temperature should not exceed 35˚C.
(3) The unit should not be installed in any area where heat and steam are generated. The unit should

not be installed, for example, next to a conventional surface unit. Refer to the "INSTALLATION
Instructions" .

(4) Exhaust vents are provided on the back of the unit for proper cooling and air flow in the cavity. To

permit adequate ventilation, be sure to install so as not to block these vents. There should be some
space for air circulation.

(5) Be sure the exterior of the cooking container and the interior of the oven are dry. Wipe off any

moisture with a dry cloth or paper towel.

(6) The Sensor works with food at normal storage temperature. For example, chicken pieces would be

at refrigerator temperature and canned soup at room temperature.

(7) Avoid using aerosol sprays or cleaning solvents near the oven while using Sensor settings. The

sensor will detect the vapor given of by the spray and turn off before food is properly cooked.

(8) After the oven is started on sensor cooking condition, if the sensor has not detected the vapor of

the food, ERROR will appear and the oven will shut off.

Make sure the oven has been plugged in at least five minutes before checking sensor cook operation.
The cabinet should be installed and screws tightened.
(1) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
(2) Place the container on the center of tray in the oven cavity.
(3) Close the door.
(4) Touch FRESH VEG. pad. Now, the oven is in the sensor cooking condition and "FRESH",

"VEGETABLES", "SENSOR" and "COOKING" will appear in the display.

(5) The oven will operate for the first 16 seconds, without generating microwave energy.

When the AH sensor is defective (open or short), ERROR will appear in the display immediately.
If ERROR appears check sensor wire connections and/or AH sensor.
NOTE: ERROR will appear if the door is opened or STOP/CLEAR pad is touched during first stage of

sensor cooking.

(6) After approximately 16 seconds, microwave energy is produced, and the display should start to

count down the remaining cooking time and oven should turn off after water is boiling (bubbling).
If the oven does not turn off, replace the AH sensor or check the control unit, refer to explanation
below.

To determine if the sensor is defective, the simplest method is to replace it with a new replacement
sensor.
(1) Disconnect oven from power supply and then remove outer case.
(2) Discharge the high voltage capacitor.
(3) Remove the AH sensor.
(4) Install the new AH sensor.
(5) Re-install the outer case.
(6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:

6-1. Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.
6-2. Place the container on the center of tray in the oven cavity.
6-3. Close the door.
6-4. Touch FRESH VEG. pad.
6-5. The control panel is in automatic Sensor operation.
6-6. The display will start to count down the remaining cooking time, and the oven will turn off

automatically after the water is boiling (babbling).

If new sensor dose not operate properly, the problem is with the control unit.

(1) Disconnect oven from power supply and then remove outer case.
(2) Discharge the high voltage capacitor.