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1

771M -

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 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.

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.

2

771M -

Service engineers should not be exposed to the microwave
energy which may radiate from the magnetron or other
microwave 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.

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.

Power Requirements

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

Power Consumption

Microwave cooking

1.6 kW  Approx. 7 A

Top Grill mode

1.25 kW

Approx. 5.2 A

Grill cooking

Bottom Heater mode

0.85 kW

Approx. 3.5 A

Top and Bottom  mode

2.05 kW

Approx. 8.5 A

Dual cooking

Micro and Top Grill

2.8 kW

12A Approx.

Micro and Bottom Heater

2.3 kW

10A Approx.

Power Output

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

Grill heating element Power Output (Top Grill)

1200 W (600 W x 2)

Bottom heating element Power Output

800W

Case Dimensions

Width

520 mm

Height

309 mm including foot

Depth

436 mm

Cooking Cavity Dimensions

Width

349 mm

Height

207 mm

Depth

357 mm

Turntable diameter

325 mm

Control Complement

Jog Touch Control System

Clock (1:00 - 12:59) / Timer (0 - 90 minutes)

Microwave Power for Variable Cooking

 Repetition Rate;
100% ...................................... Full power throughout the cooking time
70% ........................................................  approx. 70% of FULL Power
50% ........................................................  approx. 50% of FULL Power
30% ........................................................  approx. 30% of FULL Power
10% ........................................................  approx. 10% of FULL Power

FUNCTION KEYS:
LESS (

)/MORE (

) keys, WEIGHT CONVERSION key

TIMER key, PIZZA key, BREAKFAST key,
AUTO COOK key, AUTO DEFROST key, MICROWAVE POWER LEVEL key
DUAL key, GRILL key, OVEN key, STOP / CLEAR key,
AUTO MINUTE  / START key, CLOCK key, TIME/WEIGHT knob

Set Weight

Approx. 19 kg

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 QACCBA004URE1 should be used.

3

771M -

1. Control panel
2. Oven lamp
3. Grill heating element (Top Grill)
4. Door opening button
5. Waveguide cover
6. Oven cavity
7. Turntable motor shaft
8. Grill heating element

(Bottom Heater)

9. Door seals and sealing surfaces
10.Ventilation openings
11.Outer cabinet
12.Power supply cord

R-771

SNACK

AUTO

COOK

E

I

NL

GB

D

F

WATT

+

1

  min

    /KG

. .

.

.

.

.

STOP

1

4

10

11

12

5

6

7

2

3

8

9

10

Turntable 

Turntable
support 

High rack

Low rack

Turntable 
motor shaft 

Bottom 
heater

1. Ensure that the bottom heater is in the lowest

position as shown the figure. As it is possible to
move it up and down to help with cleaning.

2. Place the turntable support over the turntable

motor shaft on the floor of the cavity.

3. Then place the turntable on to the turntable sup-

port.

10

11

12

Before carrying out any work carry out 3D checks

1)

isconnect the supply.

2)

oor opened, and wedged open.

3)

ischarge high voltage capacitor.

Ensure the following:

1.

Wires must not touch:

a)

High voltage parts.
(Magnetron, high voltage transformer, high voltage capacitor and high voltage rectifier assembly)

b)

Parts that become hot.
(Heating elements, oven lamp, oven cavity magnetron and high voltage transformer)

c)

Sharp edges.
(Bottom plates, oven cavity, waveguide flange, chassis support and other metallic parts)

d)

Movable parts.
(Fan blade, any motor, switch, switch lever and open button)

2.

Positive lock connectors are fitted correctly.  Ensure the locking pin is located correctly.

3.

Wires are connected correctly as per pictorial diagram.

4.

No wire leads are trapped by the outer wrap.

4

771M -

The following levels of microwave power are given.

SETTING

100%

32 sec. ON

Approx. 100%

70%

24 sec. ON

8 sec. OFF

Approx. 70%

50%

18 sec. ON

14 sec. OFF

Approx. 50%

30%

12 sec. ON

20 sec. OFF

Approx. 30%

10%

6 sec. ON

26 sec. OFF

Approx. 10%

Note:

The On/Off time ratio does not exactly correspond
to the percentage of microwave power, because
approx. 3 seconds  are needed for heating up the
magnetron filament.

Power level

ON time

OFF time

100%

48 sec.

0 sec.

70%

36 sec.

12 sec

50%

26 sec.

22 sec.

30%

16 sec.

32 sec

10%

8 sec.

40 sec

Power level 0% can not be programmed in Dual Cooking
condition.

After the same cooking mode is carried out for more than
the specified cooking time, the power output is automati-
cally reduced by turning the control relays on and off
intermittently, as shown in the table below. This is to
protect the oven door against temperature rising.

Specified cooking

Limited power

Time base

Cooking mode

time (minutes)

output (%)

(seconds)

Microwave

20

70

32

Top grill

30

50

48

Bottom heater

45

50

48

Top grill and Bottom

15 (Top)

50

48

heater or Oven cooking

15 (Bottom)

50

48

Micro. + Top

20 (Micro.)

70

48

grill heater

15 (Grill)

50

48

Microwave +

20 (Micro.)

70

48

bottom heater

15 (Heater)

50

48

1. In case of Automatic operations, the limitations of

power output are not carried out.

2. In case that the stop key is pressed or the oven door is

opened during cooking, the limitations of power output
are carried out after the total cooking time beyond the
specified cooking time.

3. In case of the two or more same cooking modes  are

carried out,  the limitations of power output are carried
out after the total cooking time beyond the specified
cooking time.

4. In case of the two or more different cooking modes  are

carried out,  the specified cooking time is started to
count from the point when the cooking mode is changed.

5. If the cooking mode has the power level display, the

power level is also displayed when the limitations of
power output are carried out.

D

U

A

L