R-962M - Sharp Home Appliance Service Manual (repair manual)

R-962M - 1

TABLE OF CONTENTS

SERVICING ................................................................................................................................................. 2
CAUTION/WARNING .................................................................................................................................. 3
PRODUCT DESCRIPTION .........................................................................................................................  3
VIEW OF OVEN ..........................................................................................................................................  4
OPERATION DATA ....................................................................................................................................  4
FUNCTION OF IMPORTANT COMPONENTS ..........................................................................................  5
OUTPUT POWER TEST PROCEDURE ..................................................................................................... 6
TOUCH CONTROL ASSEMBLY ............................................................................................................... 11
COMPONENT REPLACEMENT AND ADJUSTMENT .............................................................................. 18
WIRING/RE-WIRING ................................................................................................................................  19
MICROWAVE MEASUREMENT ............................................................................................................... 20
WIRING DIAGRAM ...................................................................................................................................  21
CONTROL PANEL CIRCUIT ..................................................................................................................... 23
PRINTED WIRING BOARD ....................................................................................................................... 24
PARTS LIST .............................................................................................................................................. 26

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

S09950R962M//

E

900W

Jet Convection & Grill

Jet Convection & Grill

Master Chef

R-962M - 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.

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 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.

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

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.

R-962M - 3

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. 90 sec.)
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.)

SENSNCOOK pads

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 START pad, TIMER pad INFO pad

CONVERSION pad, AUTO START/CLOCK pad

Set Weight

Approx. 27 kg

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

R-962M - 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

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.

Closing the oven door activates all door interlock switches
(1st. 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

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%

13

14

15

16

1             2        3         4        5     6     17

7

10       8        9

11

12