R-952M - Sharp Home Appliance Service Manual (repair manual)

R-952M  -  1

S09949R952M//

Page

SERVICING ................................................................................................................................................. 1
CAUTION WARNING / PRODUCT DESCRIPTION .................................................................................... 3
VIEW OF OVEN ..........................................................................................................................................  4
OPERATION DATA ....................................................................................................................................  4
FUNCTION OF IMPORTANT COMPONENTS ........................................................................................... 5
OUTPUT POWER TEST PROCEDURE ....................................................................................................  6
TOUCH CONTROL  PANEL ........................................................................................................................ 9
COMPONENT REPLACEMENT AND ADJUSTMENT .............................................................................. 15
WIRING / RE-WIRING ............................................................................................................................... 16
MICROWAVE MEASUREMENT ..............................................................................................................  17
WIRING DIAGRAMS ................................................................................................................................. 18
PARTS LIST .............................................................................................................................................  23
OVEN PARTS ............................................................................................................................................ 26
CONTROL PANEL AND DOOR PARTS ................................................................................................... 27
MISCELLANEOUS/PACKING AND ACCESSORIES ................................................................................ 28

In interests of user-safety the oven should be restored to
its original condition and only parts identical to those
specified should be used.

E

R-352

R-352

LESS

MORE

MORE

g  oz

g  oz

Kg  Lb

Kg  Lb

POWER

POWER

LEVEL

LEVEL

STOP/

STOP/

CLEAR

CLEAR

START

AUTO MINUTE

AUTO MINUTE

TIMER

TIMER

Kg/Lb

Kg/Lb

AUTO START

AUTO START

CLOCK

CLOCK

KG

TURN

STIR

PCS MICRO COOK

R-952M  -  2

High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier assembly, High voltage

harness.

1)  

isconnect the supply.

2)  

oor opened, and wedged open.

3)  

ischarge 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 connection of the high-voltage capacitor (that is, of the connecting lead
of the high-voltage rectifier) against the chassis using a screwdriver with an insulated handle.

Sharp recommend that wherever possible, fault-finding is carried out with the supply disconnected.  In some
cases, it may be necessary to connect the supply with  the cover removed to carry out fault investigation in
the control circuitry.  In such cases, the high voltage circuit should be disabled as described below to reduce
the hazards:-

•

Carry out 3D checks (see above).

•

Disconnect the supply leads from the high voltage transformer, making a note of the polarity.

•

Insulate  the connectors, ensuring they are positioned away from the transformer and fastened there.

•

Connect any relevant test equipment e.g. voltmeter.

•

Reconnect the oven to the supply, then close the door.

•

Note the results of the test, taking care to keep clear of the operational oven.

•

Carry out 3D checks (see above).

•

Reconnect the leads to the transformer.  Take care to observe correct polarity.

•

Carry out 4R checks (see below).

Microwave ovens should not be used without a load.   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 one (1) minute,
set the power level to HIGH (100%) and push the start key. When the one (1) minute has elapsed (timer at zero)
carefully check that the water is now hot.

1)

econnect all leads removed from components during testing.

2)

eplace the outer case (cabinet).

3)

econnect the supply.

4)

un the oven. Check all functions.

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

IMPORTANT: If the oven becomes inoperative because of a blown fuse F8A in the 1st latch switch - monitor

switch circuit, check the 1st latch switch and monitor switch before replacing the fuse F8A.

Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with following
parts will result in electrocution:-

R-952M  -  3

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

The parts marked '*' on the parts list and schematic
diagram have voltages in excess of 250V.

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

All the parts marked "

∆

" on the parts list may cause undue

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

Do not become exposed to radiation from the
magnetron or other parts conducting microwave
energy.  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.

THE WIRES IN THIS MAINS LEAD ARE COLOURED IN

ACCORDANCE WITH THE FOLLOWING CODE:
GREEN-AND-YELLOW : EARTH        BLUE : NEUTRAL        BROWN : LIVE

If the mains lead is replaced, only part number QACCBA004WRE1 should be used

Power Requirements

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

Power Consumption

Microwave cooking  1.4 kW Approx. 6.3A

Dual cooking

(Microwave and Grill)  2.6kW Approx. 10.8A

(Microwave and Convection)  2.7kW Approx. 11.8A

Power Output

900 watts nominal of RF microwave energy (measured by method of IEC 705)
Operating fequency 2450 MHz

Convection heating element Power Output

1.3kW

Grill heating element Power Output

1.2kW (600W x 2)

Case Dimensions

Width 550 mm

Height 342 mm (including foot)

Depth 524 mm

Cooking Cavity Dimensions

Width 390 mm

Height 240 mm

Depth 395 mm

Turntable diameter

360mm

Control Complement

Touch Control System

Timer (0 - 99 min.)
Microwave Cooking Control

HIGH ...........................................  Full power throughout the cooking time
MEDIUM HIGH ............................................  approx. 70% of FULL Power
MEDIUM ......................................................  approx. 50% of FULL Power
MEDIUM LOW .............................................  approx. 30% of FULL Power
LOW .............................................................  approx. 10% of FULL Power

Convection temperature control range;
250˚C, 230˚C, 220˚C, 200˚C, 180˚C, 160˚C, 130˚C, 100˚C, 70˚C and 40˚C

Time pad (10 MIN., 1 MIN., 10 SEC.)

CONVENIENCE FOODS (FROZEN/CHILLED/AMBIENT) pad

AUTO COOK / AUTO DEFROST pads

Kg.Lb / g.oz pads, LESS(

)/MORE(

) pads

MICROWAVE POWER LEVEL pad, CONVECTION TEMP pad

DUAL COOK pad, GRILL pad, STOP/CLEAR pad

AUTO MINUTE TIMER/START pad, TIME/HOLD pad

CONVERSION pad, AUTO START/CLOCK pad

Set Weight

Approx. 27 kg

R-952M  -  4

13.Air vent openings
14.Outer cabinet
15.Back plate
16.Power supply cord

1. Oven door
2. Door hinges
3. Quarts grill
4. Oven lamp
5. Convection air opening
6. Waveguide cover

7. Control panel
8. Coupling
9. Holes for safety door latches
10.Oven cavity
11.Door seals and sealing surface
12.Door safety latches

13

14

15

16

1             2        3         4        5     6

7

10       8        9

11

12 

32 sec. ON

24 sec. ON

18 sec. ON

12 sec. ON

6 sec. ON

8 sec. OFF

14 sec. OFF

20 sec. OFF

26 sec. OFF

HIGH

MEDIUM HIGH

MEDIUM

MEDIUM LOW

LOW

Approx. 70%

100%

Approx. 50%

Approx. 30%

Approx. 10%

Closing the oven door activates all door interlock switches
(1st. latch switch, 2nd. latch switch and stop switch).

IMPORTANT:
When the oven door is closed, the contacts COM-NC of
the monitor switch must be open. When the microwave
oven is pluged in a wall outlet (230-240V, 50Hz), 240 volts
A.C. is supplied to the point A1 + A3 in the control unit.

NOTE 1.  If the oven has not been used for more than two

minutes, the contacts of the relay RY6 will be
opened and the control unit will not be energized.
Open and close the door, the control unit will
resume.

NOTE 2.  If the clock is set, this energy save mode does

not work.

1. The display flashes "88:88"
2. To set any programmes or set the clock, you must first

touch the STOP key.

3. "  :  " appears in display.

NOTE: When the oven door is opened, the oven lamp

comes on at this time.

Enter a desired cooking time with the touching Time key
and start the oven with touching START key.

CONNECTED COMPONENTS

RELAY

Oven lamp, Turntable motor

RY1

High voltage transformer

RY1 + RY2

Fan motor

RY6

When the oven door is opened during a cooking cycle, the
switches come to the following condition.

Switch

Contact

          Condition
During

Oven Door

Cooking

Open(No cooking)

Monitored latch Switch COM-NO

Closed

Opened

 Monitor Switch

COM-NC

Opened

Closed

 Stop switch

COM-NO

Closed

Opened

The following levels of microwave power are given.