R-252M (serv.man2) - Sharp Home Appliance Service Manual (repair manual)

R-252M   1

SERVICING

PRODUCT SPECIFICATIONS

GENERAL INFORMATION

APPEARANCE VIEW

OPERATING SEQUENCE

FUNCTION OF IMPORTANT
COMPONENTS

TROUBLESHOOTING GUIDE
AND TEST PROCEDURE

TOUCH CONTROL PANEL

COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE

MICROWAVE MEASUREMENT

WIRING DIAGRAM

PARTS LIST

This Manual has been prepared to provide Sharp Corp. Service
engineers with Operation and Service Information.

It is recommended that service engineers carefully study the entire
text of this manual, so they will be qualified to render satisfactory
customer service.

CAUTION

MICROWAVE RADIATION

Service engineers should not be exposed to the microwave
energy which may radiate from the magnetron or other micro-
wave generating devices if it is improperly used or connected.
All input and output microwave connections, waveguides, flanges
and gaskets must be secured. Never operate the device without
a microwave energy absorbing load attached. Never look into
an open waveguide or antenna while the device is energized.

WARNING

Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is not any other visible damage with the oven.

Servicing and repair work must be carried out only by trained
service engineers.

All the parts marked "*" on parts list are used at voltages more than
250V.

Removal of the outer wrap gives access to potentials above 250V.

All the parts marked "

∆

" on parts list may cause undue microwave

exposure, by themselves, or when they are damaged, loosened or
removed.

R-252M   2

1) Disconnect the supply.
2) Door opened, and wedged open.
3) Discharge high voltage capacitor.

WARNING: AGAINST THE CHARGE OF THE

HIGH-VOLTAGE CAPACITOR.

The high-voltage capacitor remains charged about
60 seconds after the oven has been switched off.
Wait for 60 seconds and then short-circuit the con-
nection of the high-voltage capacitor (that is, of the
connecting lead of the high-voltage rectifier) against
the chassis with the use of an insulated screwdriver.

Sharp recommend that wherever possible fault-finding is
carried out with the supply disconnected. It may in, some
cases, be necessary to connect the supply after the outer
case has been removed, in this event carry out 3D
checks and then disconnect the leads to the primary of
the high voltage transformer. Ensure that these leads
remain isolated from other components and the oven
chassis. (Use insulation tape if necessary.) When the
testing is completed carry out 3D checks and reconnect
the leads to the primary of the high voltage transformer.

1) Reconnect all leads removed from components dur-

ing testing.

2) Replace the outer case (cabinet).
3) Reconnect the supply.
4) Run the oven. Check all functions.

Microwave ovens should not be run empty. To test for the
presence of microwave energy within a cavity, place a
cup of cold water on the oven turntable, close the door
and set the microwave timer for two (2) minutes. And set
the power level to HIGH (100%) and push the start key.
When the two minutes has elapsed (timer at zero)
carefully check that the water is now hot. If the water
remains cold carry out 3D checks and re-examine the
connections to the component being tested.

When all service work is completed and the oven is fully
assembled, the microwave power output should be
checked and microwave leakage test should be carried
out.

Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with following parts will
result in electrocution.
High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier , High voltage harness.

R-252M   3

THE WIRES IN THIS MAINS LEAD ARE COLOURED IN ACCORDANCE WITH THE FOLLOWING CODE:

GREEN-AND-YELLOW

: EARTH

BLUE

: NEUTRAL

BROWN

: LIVE

Power Requirements

230 - 240 Volts
50 Hertz
Single phase, 3 wire earthed

Power Consumption

1.24 kW

Power Output

800 W nominal of RF microwave energy (measured by method of IEC 705)
Operating frequency 2450 MHz

Case Dimensions

Width

449 mm

Height

282 mm including foot

Depth

385 mm

Cooking Cavity Dimensions

Width

287 mm

Height

220 mm

Depth

311 mm

Turntable diameter

272 mm

Control Complement

Touch Control System

Clock (1.00 - 12.59 or 0.00 - 23.59) - 12HR or 24HR setting
Timer (0 - 99 minutes and 90 seconds)

Microwave Power for Variable Cooking

Repetition Rate;
100P (HIGH) .......................... Full power throughout the cooking time
70P (MEDIUM HIGH) ...............................  approx. 70% of Full Power
50P (MEDIUM) .........................................  approx. 50% of Full Power
30P (MEDIUM LOW) ................................  approx. 30% of Full Power
10P (LOW) ................................................  approx. 10% of Full Power

Time pads, Instant Cook pads
AUTO COOK pad, AUTO DEFROST pad
Weight pads, LESS/MORE pads
POWER LEVEL pad, STOP/CLEAR pad
START/AUTO MINUTE pad, TIMER pad
Weight conversion pads
AUTO START/CLOCK pad

Set Weight

Approx. 13.3 kg

R-252M   4

1. Place the roller stay on the floor of the oven cavity, engaging

shaft into turntable motor shaft.

2. Then place the turntable on roller stay.

4. Oven lamp
5. Control panel
6. Rubber seal
7. Door latch openings
8. Oven cavity
9. Door seals and sealing surfaces
10.Safety door latches
11.Ventilation openings
12.Outer case
13.Power supply cord

OVEN
1. Door
2. Door hinges
3. Waveguide cover

3

4

1

10

7

6

2

9

8

11

5

12

13

STIR

KG PCS

TURN

COOK

MICRO

10min.

10sec.

1min.

FRESH FISH

MINCED MEAT

FRESH VEG.

CANNED FOOD

SPONGE PUDDING

CAKE

JACKET POTATOES

BOILED POTATOES

RICE/PASTA

Instant Cook

AUTO

COOK

Kg Lb

POWER

LEVEL

TIMER

Kg/Lb

STOP/

CLEAR

START

AUTO MINUTE

AUTO START

CLOCK

LESS

MORE

g  oz

AUTO

DEFROST

2

3

5

10

7

12
13

4

6

8
9

11

1. DIGITAL DISPLAY
2. TIME keys
3. INSTANT COOK keys
4. AUTO COOK key
5. AUTO DEFROST key
6. WEIGHT keys
7. LESS/MORE keys
8. POWER LEVEL key
9. STOP/CLEAR key
10. START/AUTO MINUTE key
11. TIMER key
12. AUTO START/CLOCK key
13. WEIGHT CONVERSION key

1

Turntable 

Roller stay

Seal packing