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R-641M -

S9807R641M///

Page

SERVICING ................................................................................................................................................. 2
CAUTION WARNING / PRODUCT DESCRIPTION .................................................................................... 3
OPERATION SEQUENCE / FUNCTION OF IMPORTANT COMPONENTS .............................................  4
TEST PROCEDURE ...................................................................................................................................  5
TOUCH CONTROL  PANEL ........................................................................................................................ 8
COMPONENT REPLACEMENT ................................................................................................................ 12
MICROWAVE MEASUREMENT ..............................................................................................................  13
WIRING / RE-WIRING ............................................................................................................................... 14
WIRING DIAGRAMS ................................................................................................................................. 15
PARTS LIST .............................................................................................................................................  18
OVEN PARTS ............................................................................................................................................ 21
CONTROL PANEL AND DOOR PARTS ................................................................................................... 22
MISCELLANEOUS .................................................................................................................................... 23

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

700W

700W

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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.

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 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.

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 investi-
gation 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).

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R-641M -

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 QACCBA004URE1 should be used

Power Requirements

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

Power Consumption

Microwave cooking

1350 W  Approx. 6.3A

Grill Cooking

1050 W  Approx. 4.4A

Power Output

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

Grill heating element Power Output (Top Grill)

1000 W (500 W x 2)

Case Dimensions

Width

449 mm

Height

282 mm including foot

Depth

374 mm

Cooking Cavity Dimensions

Width

260 mm

Height

194 mm

Depth

313 mm

Turntable diameter

272 mm

Control Complement

Simple Touch Control System

Microwave Power for Variable Cooking

Repetition Rate;
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

Set Weight

Approx. 14 kg

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Closing the door activates all door interlock switches
(Monitored latch switch, and stop switch.)

When the microwave oven is preset for variable cooking
power, the 240 volts is supplied to the high voltage
transformer intermittently within a 32-second time base
through the relay contact which is coupled with the
current-limiting relay RY3. The following levels of micro-
wave power are given.

SETTING

32 sec. ON

24 sec. ON

18 sec. ON

12 sec. ON

6 sec. ON

8 sec. OFF

14 sec. OFF

20 sec. OFF

28 sec. OFF

HIGH

MEDIUM
 HIGH

MEDIUM

MEDIUM 
LOW

LOW

Approx. 70%

Approx. 50%

Approx. 30%

Approx. 10%

Note:

The On/Off time ratio does not exactly corre-
spond to the percentage of microwave power,
because  approx. 2 seconds  are needed for
heating up the magnetron filament.

100%

26 sec. OFF

LATCH HOOK

STOP SWITCH

MONITORED
LATCH SWITCH

MONITOR SWITCH

LATCH
HEADS

OPEN LEVER

DOOR OPEN BUTTON

DOOR

The door can be opened by pushing the open button on
the control panel. When the open button is pushed, the
open lever pushes lower latch head on the door upward.
The latch head is linked with the lower latch head, so now,
the door can be opened.