Sharp R-6280 User manual

R -6280
SHARP SERVICE MANUAL
S3702R6280J//
MICROWAVE OVEN
In the interests of user-safety the set should be restored IO its ongina!
condition and only parts identical to those specified should be zsm
TABLE OF CONTENTS Page
FOREWORD ,....................,............I......................~....................~..............................................................,.....,... 1
CAUTION, MICROWAVE RADIATION ....................................~...........................................................~........ 1
PRODUCT DESCRIPTION ,..,.,...,,..................................,.~..........~...,...,..,.,...,.......,,.,..................,.........,..,......,, 2
OPERATION ..........................*............................................................................................................................ 3
SERVICING ..........~....................~............~.........................~.....................~...........................................................
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURES
MICROWAVE MEASUREMENT ................................................... 1;
PROCEDURE .......................................................................................... 16
PICTORIAL DIAGRAM AND SCHEMATIC DIAGRAM .......................................(..,..,......,...........,..,...,.. 17
PARTS LIST .................................................................................................................................................... 18
PACKING AND ACCESSORIES ,..~...........................,..................~.......,,......,,...,.......,........,,..,.....,..~............. 22
SHARPCORPORATION

R -6280

R-6280
SERVICE MANUAL
SHARP
MICROWAVE OVEN
R-6280
FOREWORD
This Manual has been prepared to provide Sharp Corp. Service
Personnel with complete Operation and Service Information for
the SHARP MICROWAVE oven, R-6280.
It is recommended that service personnel carefully study the
entire text of this manual so they will be qualified to render
satisfactory customer service.
Check interlock switches and door seal carefully. Special at-
tention should be given to avoid electrical snack and microwave
radiation hazard.
CAUTION
MICRQWAVE RADIAfiON
Personnel 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 abs’orbing load attached. Never look into
an open waveguide or antenna while the device is energized.
OSAKA, JAPAN
PRODUCT DESCRIPTION

R -6280
PRODUCTION DESCRIPTION
EXPLANATION OF MICROWAVE COOKING
The Sharp Microwave Oven uses microwave energy to
produce heat in the food to be cooked. Unlike con-
ventional ovens microwave energy will cook foods
without applying external heat.
Microwaves, which are short electromagnetic waves
of RF (radio frequency) energy, pass through materials
such as glass, paper, china and most plastics. Materi-
als such as metal and aluminum foil tend to reflect
microwaves and may be used only as recommended in
the cooking instructions. Materials with a high
moisture content, like most foods, will absorb micro-
wave energy. As the microwave energy at a frequency
of 2450 Megahertz enters the food, the molecules align
themselves with the energy. Because the microwaves
are changing polarity every half cycle, the food mole-
cules are changing direction every half cycle or oscil-
lating back and forth 4,900,000,000 times per second.
This high speed oscillation causes friction between the
molecules, thereby converting the microwave energy
to heat.
SPECIFICATION
ITEM DESCRIPTION
Power Requirements / -240 Volts
! 50 Hertz
: Single phase, 3 wire earthed
Power Consumption
Power Output
Case Dimensions
---
Cookrng Cavity Dimensions
--
Control Complement
Set Weight
1 13oow
i 650 watts normal of RF microwave energy (2 liter water load)
Operating frequency of 2450MHz .
/ Width 520 mm
! Height 318 mm including foot
j Depth 393 mm
Width 345 mm
Height 217 mm
Depth 364 mm
60 min. Dual Speed Timer
Microwave Power for Variabie Cooking
Repetition Rate;
HIGH ...............~...............
M ED H1GH Full power throughout the cooking time ............................................ approx. 70% of Full Power
MED .................................I..................... approx. 50% of Full Power
MED LOW DEFROST ........................ approx. 30% of Full Power
LOW ....................................................... approx. 10% of Full Power
Ac>r>rox. 17.5 kg

R-6280
OPERATION
NORMAL COOKING SEQUENCE
To start cooking:
1.
2
3
4
Place the food to be cooked in the oven and close the door
firmly.
Set the cooking control for a desired position.
Set the timer for a desired cooking time. The oven lamp
will come on immediately.
Push the cook button. The turntable motor will rotate to
indicate the oven is in the cook cycle, and the timer motor
will operate.
5.
Note: If the oven door IS opened during the cook cycle,
the oven will go out of the cook cycle (no microwave
energy) and the timer will stop. This is done so the exact
cooking time remains on the timer. To restore cooking
operation, the door must be closed and the cook button
must be pushed again.
At the end of the cook cycle (time returned to ” 0 “), the
timer bell will ring. The oven will stop supplying the
microwave energy.
DESCRIPTION OF OPERATING SEQUENCE
The following is a complete descrrption of component func-
tions during the three stages of oven operation.
OFF CONDlTiON
With the timer dial at ” 0 ” position and the door closed, no
components in the oven will operate (Figure O-l). But rhe
oven lamp will come on with the door opened.
IDLE CONDITION
Closing the door activates latch switch. Selecting a cooking
time closes the timer contacts leading to the oven lamp and
latch switch, therefore the oven lamp comes on (Figure O-2).
COOKiNG CONDITION
1. FULL POWER COOKING
When the cooking control set to HIGH position and the
start button is pushed ,with the timer set, the following
operation occurs: (Figure O-3).
l-l. Timer motor, turntable motor and fan motor are
energized.
l-2. The 240 volts A.C. is supplied to a primary winding
of the power transformer through the vari-switch, and
is converts 3.5 volts A.C. output on the filament
winding and approximately 1,900 volts A.C. on the
high voltage winding.
1-3. The filament winding voltage heats the magnetron
filament and H.V winding voltage is sent to voltage
doubler circuit consisting of a high voltage capacitor
and a rectifier.
l-4. The microwave energy produced by the magnetron
tube is channeled into the oven cavity where the food
is placed to be cooked.
1-5. Upon completion of the selected cooking time, the
timer contacg open and the oven reverts to the off
condition.
in the case cook (latch) switch falls with its contacts closed
when the door is opened, the monitor switch wrll form a
short circuit through the fuse and the cook (latch! switch.
2. VARIABLE COOKING
When the cooking control set to MED HIGH, MED, MED
LOW DEFROST, LOW position and the cook button is
pushed, the following operation occurs.
2-l. Above l-l operation occurs.
2-2. The varl-motor rotates at two (2) revolutions per
minute. In case the cooking control is set to MED
HIGH, the 240 volts A.C. is supplied to the power
transformer intermittently through the vari-switch
which is operated, at 24 seconds ON and 6
seconds OFF repetrtlon rate by means of a cam
linked to the vari-motor shaft. The repetition rate
for others are as follows:
MED : 16.5 seconds ON, 13.5 seconds OFF.
FEpR&‘$y : 9 seconds ON, 21 seconds OFF.
LOW : 5 seconds ON, 25 seconds OFF.
2-3. The power transformer converts while the 240 volts
A.C. is supplied to the primary winding.
2-4. Then above 1-3, 1-4, and l-5 operations occur.
I
3

R -6280
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R-6280
DESCRIPTION AND FUNCTION OF COMPONENTS
OVEN TEMP. FUSE
The temp. fuse located on the top wall of the oven
cavity is designed to prevent damage to the unit if the
foods in the oven catch fire due to overheating
produced by unproper setting of cooking time or failure
of the timer. Open temp. 145 “C(293 ‘F) not resetable.
MAGNETRON TEMP. FUSE
The temp. fuse located on the waveguide side wall is
designed to prevent damage to the magnetron if an
over heated condition develops in the tube due to
cooling fan failure, obstructed air ducts, dirty or
biocked air intake, etc.
Under normal operation, the temp. fuse remains closed.
However, when abnormally high temperatures are
reached within the magnetron the fuse will open at
145 “C(293 ‘F), causing the oven to shut down.
This is a fuse and it does not reset.
UPPER LATCH SWITCH
The switch is activated by the upper iatch head on the
door. When the door is opened, the switch interrupts
the circuit to all components (except oven lamp). A
cook cycle cannot take until the door is firmiy ciosed
and the start button depressed with the timer ser.
COOK (LOWER LATCH) SWlTCH
This switch functions both as a cook(iower iatch)
switch. Operation are as follows.
1. When the door is closed, the latch head moves
downward the cook switch lever which causes not
to close the cook(lower latch) switch contacts.
2. When the start button is pressed, it operates the
cook switch lever moving latch head downward
farther.
The cook switch lever now depresses the plunger
of the switch closing its COM- NO contacts (ON
condition).
3. When the open button is pressed, it pushes up the
cook switch lever raising the latch heads. As the
cook switch lever is raised, the switch plunger is
released, opening the COM-NO contacts of the
switch (OFF condition). The cook switch lever is
also returned to original position.
MONITOR SWITCH
The monitor switch is activated (the contacts opened)
by the latch head on the door while the door is closed,
The switch is intended to render the oven inoperative
by means of blowning the fuse when the contacts of
the cook switch, fail to open when the door is opened.
Functions:
1. When the door is opened, the monitor switch con-
tacts close (to the ON condition) due to their being
normally opened. At this time the cook(lower
latch) switch are in the OFF condition (contacts
open) due to their being normally open contacts
switches.
2.
3.
As the door goes to a closed position, the monitor
switch contacts are first opened and then the upper
latch switch contacts close. The cook (lower
latch)switch contacts close when the start button
is depressed (In case of opening the door, each of
these switches operate inversely.)
If the door is opened, and the cook(lower latch)
switch contacts fail to open the fuse blows simul-
taneously with closing of the monitor switch con-
tacts.
CAUTION:BEFORE REPLACING A BLOWN FUSE
M6.3A TEST THE COOK(LOWER LATCH)
SWITCH AND MONITOR SWITCH FOR
PROPER OPERATION.
(REFER TO CHAPTER “TEST PROCE-
DURE”).
DOOR OPEN MECHANISM
The door is opened by pushrng the open button on the
control panel, refer to the Figure D-i.
When the open button Is pushed, the open lever
pushes up the switch lever. and then the switch lever
pushes up the latch head.
The latch head are moved upward and released from
the latch hook. Now the door will open.
\
UPPER
LATCH
SWITCH
MONITOR
SWITCH
COOK
(LATCH)
SWITCH
COOK
‘SWITCH
LEVER
J
/J al’x< ‘h-
O/
3 A.
START ‘L
BUTTON \OPEN
BUTTON
Fiaure D-l. Door ODen Mechanism
5

R -6280
TIMER OVEN LAMP
Timer switch contacts:
The timer switch contacts are mechanically opened or
closed by turning the timer knob located on the timer
motor shaft.
These contacts cotroi the current path to the oven lamp
and fan motor,etc.
The oven lamp illuminates the interior of the oven so
that food being cooked can be examined visually
through the door window without having to open the
door.
FAN MOTOR
Timer bell:
The bell striker is mechanically driven by the timer
motor and rings once at the end of the cook cycle.
The fan motor drives a blade which draws cooling air
through the back vents. This cooling air is directed
through the air vanes surrounding the magnetron and
cools the magnetron. This air is channeled through the
oven cavity to remove steam and vapors given off from
the heating foods. It is then exhausted at the back of
the oven cavity.
Timer motor:
When the timer reaches the U “point of the scale, the
timer contacts opens the circuit to oven lamp and
power transformer etc, and the cook cycle stops.
SERVICING
TROUBLESHOOTING GUIDE
When troubleshooting the microwave oven, it is
helpfull to follow the Sequence of Operation in per-
forming the checks. Many of the possible causes of
trouble will require that a specific test be performed.
These tests are given a procedure letter which will be
found in the “Test Procedure”section.
IMPORTANT: If the oven becomes inoperative be-
cause of a blown fuse in the monitor
switch, cook switch circuit, check the
monitor switch and cook switch before
replacing the monitor fuse.
PROBLEM POSSIBLE CAUSE TEST PROCEDURE OR
CORRECTION
OFF CONDITION
iiome fuse blows when power Shorted wire in power cord or wire har-
cord is plugged into wall recepta- Replase cord or check wiring.-
ness.
cle.
Oven fuse blows when power ’ Shorted wire in power cord or wire har-
cord is plugged into wall recepta- / Replace power cord or check
ness.
cle. , and repair harness.
1 Defective monitor switch. , Procedure F.
Oven lamp does not light with / No power from service entrance.
door opened. / Check wall outlet. I
(Timer is at N ” position.) / Open wire in power cord or wire harness. Replace same or repair wir- 1
/ ing.
1 Blown fuse.
/
1 ; Check for short circuit and
/ l replace fuse.
/ Defective temp. fuse. / Procedure G.
j Defective oven lamp.
1 ! Replace oven lamp. Defective upper latch switch. / Procedure E. 1
I
/ Open or loose wire connection to the I Check wiwring.
j above components.
6

R-6280
PROBLEM POSSIBLE CAUSE / TEST PROCEDURE OR ;
I CORRECTION J
IDLE CONDITION
1Wi;!i;“,; timer set, oven lamp do 1 Defective oven lamp.
I
/ j Defective timer contacts.
/
I / Open or loose wire connection.
/ Replace oven lamp.
I Procedure H.
I Check wiring.
COOKING CONDITION
Turntable motor does not rotate 1 Defective cook(iower latch) switch. j Procedure E.
when the timer set with door / Defective upper latch switch. Procedure E.
closed and cook buttonis pushed. I Defective turntable motor ’ Replace turntable motor.
Open or loose wire connection to the Check wiring.
/ above components.
Fan motor does not rotate when / Defective fan motor. ! Check fan motor.
the timer set with door closed and
cook button is pushed. Open or loose wire connection. ~Check wiring.
/
Oven seems to be operating, but ’ Defective vari-motor. Procedure I.
little or no heat is produced in Defective magnetron. Procedure A. --
oven load. Defective rectifier.
(Variable cooking control is set at Procedure C.
HIGH position.) Defective high voltage capacitor. Procedure D.
Defective power transformer. Procedure B.
Open or loose wire connection to the Check and repair wiring
above components.
Oven operates normally when the Defective vari-motor. Procedure I.
variavle cooking control is set at ’ Open or loose wire connection.
HIGH position, but not in any ! Check wiring.
other mode. . I
Oven goes into a cook cycle but (
extremely Turntable does not rotate during cook cy- 1 Replace turntable motor or
uneven heating is , cle due to the motor failure. check wiring. /
produced in oven load. I I
Oven goes into cook cycle, but j Temp. fuse is open. 1 Procedure G.
shut down befor end of cycle. I /
1 Open or loose wire connection. Check wiring. I
7

R-6280
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
MAGNETRON ASSEMBLY TEST
DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPO-
NENTS OR WIRING.
To test for an open fiiament, isolate the magnetron from the high voltage circuit. A continuity
check across the magnetron filament leads should indicate less than 1 ohm.
To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament
leads and chassis ground. This test should indicate an infinite resistance. if there is little or no
resistance, the magnetron is grounded and must be replaced.
Power output of the magnetron can be measured by performing a water temperature rise test.
This test should only be used if above rests do not indicate a faulty magnetron and there is no
defect in the following components or wiring: rectifier, high voltage capacitor, heater transformer
and power transformer.
MICROWAVE OUTPUT POWER
Microwave output power from the magnetron can be measured by way of substitution, i.e. it can
be measured by using water load how much it can be absorbed by the water load. To measure
the microwave output power in the microwave oven, the relation of calorie and watt is used.
When P(W) heating works for t(second), approximately P x t/4.2 calorie is generated. On the
other hand, if the temperature of the water with V(ml) rises AT ( “C) during this microwave
heating period, the calorie of the water is V x AT.
The formular is as follows;
P x t li 4.2 = V x AT
P (W) = 4.2 x V x AT / t
Out condition for thE water ioad is as follows:
Water ioad ... 2000 ml, Heating time ...I29 seconds
P = 65 x “T
Measuring method;
7. Put the water load of two (2) litres on the center of the oven shelf. The water load should
be arranged in two (2) Pyrex beakers, the size of which is one (1) litre, and be placed at right
and left, side by side, on the oven shelf.
2. Measure the temperature of water before heating and also after heating during 129 seconds
by mrcrowave. and caicuiate the temperature rise. The temperature rise should be the average
of temperature differences measured in each beaker.
3. The output power should be caiculated as follows. In case the measuring result is not satis-
factory, execute the measurement several times and judge the result from the synthetic point
of view. Microwave output power should be within & 15% of the nominal one.
Calculation of output power;
Microwave output power ...P(W)=65x AT(cC)
AT = ( A-I-L +- ATR) / 2 : average temperature rise
ATL = (TL2 - TLI), ATR = (TR2 - TRl)
TL2 : water temperature after heating in left beaker
TL”; : water temperature before heating in ieft beaker
TR2 : water temperature after heating in right beaker
TRI : water temperature before heating in right beaker
Measuring condition;
As the microwave output is affected by several conditions, the measurement should be made
carefully with following attentions.
1. Initial temperature of salt water should be 10 f 1 “C. (The salt water should be contained
one (1) percent of salt.) Well and quickly stir the water and the temperature measurement
should be done immediately after heating.
2. The graduation of thermometer should be scaled by 0.1 “C at minimum and an accurate mer-
cury thermometer is recommended.
8

R-6280
TEST PROCEDURES (CONT’D)
PROCEDURE
LETTER COMPONENT TEST
3. Water container should be one (1) litre beaker made of Pyrex glass and its diameter approxi-
mately 12 cm.
B
4. Room temperature should be around 20 “C.
5. Power supply voltage should be specification voltage.
POWER TRANSFORMER TEST
DISCHARGE THE HIGH VOLTAGE CAPACITAOR BEFORE TOUCHING ANY OVEN COMPO-
NENTS OR WIRING.
Disconnect the primary input terminals and measure the resistance of the transformer with an
ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance
of the primary coil should be approximatery 1.9 ohms and the resistance of the high voltage coil
should be approximately 94 ohms, the resistance of the filament coil should be less than 1 ohm.
(HIGH VOLTAGES ARE PRESENT TO HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO
MEASURE THE FILAMENT AND HIGH VOLTAGE.)
C SILICON RECTIFIER TEST
DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPO-
NENTS OR WIRING.
Isolate the rectifier from the circuit. Usrng the highest ohm scaie of the meter, read the resistance
across the terminals and observe, reverse the leads to the rectifier terminals and observe meter
reading. If a short is indicated in both directions, or rf an infinite resistance is read in both di-
rections, the rectifier is probably defective and should be repiaced.
D HIGH VOLTAGE CAPACITOR TEST
DISCHARGE THE HIGH VOLTAGE CAPAC;TOR BEFORE TOUCHING ANY OVEN COMPO-
NENTS OR WIRING.
E
If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input
leads and check for short or open, between the terminals using an ohmmeter.
Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate
continuity for a short time and should indicate approximately IOM R once the capacitor is
charged. If the above is not the case, check the capacitor with an ohmmeter to see if it is shorted
between the terminals. if it is shorted, replace the capacitor.
SWITCH TEST
Isolate the switch and check the contacts by using an ohmmeter using the following table.
If improper operation is indicated, make the necessary switch adjustment or replacement.
Table: Switch Connection
Connection i Common Terminal-Normally Open Terminal / Common Terminal-Normally Close Terminal 1
I (COM) (NOI
i Operation ’ (COM) (NC) 1
/
I
1 Plunger released , Open ctrcuit /
I Close circuit
[ Plunger pushed / Closed circuit Open circuit

R -6280
TEST PROCEDURES (CONT’D)
PROCEDURE
LETTER COMPONENT TEST
F MONITOR SWITCH TEST
Before performing this test, make sure that the cook (lower iatch)switch is operating properly
referring to the above Switch Test Procedure.
Check the monitor switch operation by using the ohmmeter as follows.
When the door is open, the meter should indicate a closed circuit.
When the monitor switch actuater is pushed by a screw driver through the lower latch hole on
the front plate of the oven cavity with the door opened (in this condition the plunger of the
monitor switch is pushed in), the meter should indicate an open circuit.
if improper operation is indicated, replace the defective switch.
POWER TRANSFORMER
TEMP.
OHMMETER
.-
MONITOR
SWITCH
G MAGNETRON AND OVEN TEMP. FUSE TEST
A continuity check across the temp. fuse terminals should indicate a closed circuit unless the
temperature of the temp. fuse reaches approximateiy 145 “C.
An open magnetron temp. fuse indicates overheating of the magnetron assembly. If the temp.
fuse indicates a open circuit, repface the temp. fuse and check for restricted air flow to the
magnetron through the opening in the chassis, espscially the air duct.
An open temp. fuse indicate overheating of oven cavity.
H TIMER TEST
TIMER CONTACTS TEST
Advance the timer and then return to ” -, ” positron and check for continty between the terminals
If an open circuit is indicated at the ad;anced position or closed a circuit is indicated at ” 0 ”
position, replace the timer.
TIMER MOTOR TEST
Disconnect the wire read from the timer motor and check with voltage (240) to the motor coil.
If voltage is present, but the timer motor does not turn, replace the timer.
If voltage is not present, check for loose or broken wiring.
10

R-6280
TEST PROCEDURES (CONT’D)
PROCEDURE
LETTER COMPONENT TEST
I VARI-TIM ER TEST
With 240 volts A.C. applid to the vari-motor coil (3) and (4), check for continuty between the
vari-switch contacts (1 )and (2).
When the variable cooking control set at HIGH position, the meter should indicate a closed cir-
cuit.
If set at any other position refer to the following chart.
VARI-MODE ON TIME OFF TIME
HIGH Approx. 30 sec.
MED HIGH Approx. 24 sec.
MED Approx. 17 sec.
MED LOW DEFROST Approx. 9 sec.
LOW Approx. 5 sec.
Approx. 0 sec. (approx. 100% of full power)
Approx. 6 sec. (approx. 70% of full power)
Approx. 13 sec. (approx. 50% of full power)
Approx. 21 sec. (approx. 30% of full power)
Approx. 25 sec. (approx. 10% of full power)
If improper operation is indicated, replace the vari-timer. If proper operation is indicated, check
for loose or broken wire connections.
11

R -6280
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WARNING: To avoid possible exposure to microwave 2.
A. energy;
Before operating oven
1. Make sure that unlatching door slowly is ac-
companied by a click indicating actuation of
monitor switch and latch switch.
B. 2. Check visually door seal for arcing and damage.
Do not operate oven until after repair if any of fol-
lowing conditions exist;
1. Door does not close firmly against front of ap-
pliance.
To
::
3.
remove the components, proceed as follows. 4. Lift the entire case from the unit.
Disconnect oven from the power supply.
Remove the screws from the rear and along the side CAUTION: DISCHARGE THE HIGH VOLTAGE
edge of the case. CAPACITOR BEFOR TOUCHING ANY
Slide the entire case back about 3cm to free it from OVEN COMPONENTS OR WIRING.
retaining clips on the cavity face plate.
(HIGH VOLTAGE CAPACITOR AND RECTIFIER AND SHORT PROTECTOR)
1.
2.
?
L.
4.
:
2
2
U.
”
2.
3.
4.
5.
6.
me
To remove the components, proceed as follows. 5. Disconnect the wire leads and terminal of rectifier
Disconnect the oven from the power supply and from the high voltage capacitor.Now,the rectifier is
remove the outer case. free.
Discharge the high voltage capacitor. 6. Disconnect the terminals of short protector from the
Remove the one (1) screw holding the capacitor high voltage capacitor.Now,the capacitor is free.
hoider to the oven unit. CAUTION: WHEN REPLACING THE
Remove the one (I) screw holding the earth side RECTIFIER,THE EARTH SIDE TERMI-
rerminal of rectifier,and remove the capacitor holder. NAL MUST BE SECURED FIRMLY
WITH A EARTHING SCREW.
Sisconneci uven from power supply and remove
cuter case. 4 Xisconnect the filament leads from the magnetron
Discharge the high voltage capaciror. and high voltage capacitor.
Disconnect the wire leads from the power transfor- 5. Remove the two (2) screws holding the transformer
to the unit chassis.
Z?E?!
Disconneci the oven from the power supply and
remove the outer case.
Discharge the high voltage capacitor.
Disconnect wire leads from the magnetron,
Remove the one (I> screw holding the air duct.
Carefully loosen the four (4) screws holding the
magnetron to waveguide flange.
Lower the magnetron assembly until the tube is
clear of the waveguide.
‘--r-,I
me-insrail
3.
4.
There is a broken door hinge or support.
The door is bent or warped.
There is any defective parts in the latch, oven
door or microwave generating and transmission
assembly.
There is any other visible damage to oven.5.
C. Do not operate oven
I. Without the RF gasket.
2. If door is not closed.
OUTER CASE REMOVAL
HIGH VOLTAGE COMPONENTS REMOVAL
POVVER TRANSFORMER REMOVAL
6. Remove the transformer.
MAGNETRON REMOVAL
1. Re-install the magnetron to the waveguide flange
by the four (4) mounting screws.
2. Install the air duct to the magnetron by one (1 )
mounting screw.
3. Re-connected the wire leads to the magnetron.
CAUTION: WHEN REPLACING THE MAGNETRON,
BE SURE THE R.F. GASKET IS IN
PLACE AND THE MAGNETRON
MOUNTING SCREWS ARE TIGHTENED
SECURELY.
12

UPPER LATCH SWITCH, COOK (LATCH) SWITCH AND MONITOR SWITCH REMOVAL
1. Disconnect the oven from the power supply and remove the Re-install
outer case. 1. Re-install each switch in its place.
2. Discharge the high voltage capacitor. The upper latch switch is in the upper position and the
3. Disconnect the wire leads from the switch. monitor switch is in the middle position and the cook
4. Remove the two (2) screws holding the latch hook from (latch) switch’is in the lower position.
the oven cavity flange, and remove the latch hook.
5.- To remove the individual switch from the latch hook,
push outward the one (1) retaining tab holding the switch
in place.
TURNTABLE MOTOR REMOVAL
1.
2.
3.
4.
Disconnect oven from power supply.
Remove the turntable motor cover by removing the
two (2) screws.
Disconnect the wire lead from turntable motor and
remove the two (2) screws holding the turntable
motor.
Turntable motor is free now.
TURNTABLE COUPLING REMOVAL
1.
2.
Remove the turntable motor, refer to “Turntable
Motor Removal”.
Remove the seal ring (O-ring).
At this time turntab1.e coupling will be free.
2. Reconnect the wire leads to each switch.
3. Secure the latch hook (with the two (2) mounting screws)
to the oven cavity falange.
4. Make sure that the monitor switch is operating properly.
Refer to the Test Procedure and the Adjustment procedure.
NOTE: This screw must be used the
specified scrwv
(XFPSD40PlOOOO) as fist
on Parts List.
X FPSD40P10000
m
f7Gz Figure C-l.
TURN TABLE
BOTTOM
OVEN CAVITY
Figure C-2. Turntable Coupling
CONTROL PANEL ASSEMBLY AND COMPONENTS REMOVAL
The complete control panel should be remove for replacement
of the components. To remove the control panel proceed as
follows:
TIMER
1. Disconnect the oven from the power supply and remove the
outer case.
1. Remove the timer knob from the timer shaft.
2. Remove the two (2) screws holding the timer to the control
panel frame.
2. Discharge the high voltage capacitor.
3. Disconnect the wire leads of main wire harness from the
control panel components.
VARI-MOTOR
1. Remove the variable cooking control knob from the vari-
motor shaft.
4. Remove the one (1) screw holding the control panel flame 2. Remove the two (2) screws holding the vari-motor to the
to the oven cavity. control panel back plate.
5. Lift up the control panel assembly and pull it forward.
Replacement of individuai component is as follows:
13

R-6280
LATCH SWITCH, COOK (LATCH) SWITCH AND
MONlTOR SWITCH ADJUSTMENT
in case the upper latch switch and cook (latch) switch do not
operate properly due to a misadjustment, the following adjust-
ment should be taken.
1. Loosen the two (2) screws holding the latch hook.
2. With the door closed and the start button pushed, adjust
the latch hook by moving it back and forward, or up and
down. in and out play of the door allowed by the latch
hook should be lessthan 0.5mm.
The vertical position of the latch hook should be placed
where the cook (latch) switch has activated with the door
closed and the start button pushed.
3. Secure the screws with washers firmly.
4. Now, make sure the upper latch and cook (latch) switchs
operation. if the upper latch and cook (latch) switchs have
activated with the door ciosed and the start button pushed,
loosen the two (2) screws holding the latch hook and adjust
the latch hook position.
UPPER
LATCH
SWITCH
After the adjustment, make sure of the following points:
1. The latch and cook (latch) swatches Interrupt the circuit
before the door can be opened.
2. The monitor switch contacts close when the door IS
opened.
3. Re-install the outer case and check for microwave leakage
around the door wrth an approved microwave survey meter.
(Refer to MIcrowave Measurement Procedure.)
BUTTON BUTTON
.
Figure C-3. Latch Switches Adjustment
LATCH HEAD REMOVAL DOOR DISASSEMBLY
Remove the door assemb!y, refer to items 1 through 5 of
“‘Door Replacement”.
8eplacement of latch head a:e as ioliows:
f Place the door assembly on a soft cloth with latches facing
3. Lift up the choke cover.
4. Now the choke cover isfree from the door panel.
5. Remove the latch spring from the door panel.
6. Pushing up the latch head, it is now free from door panel.
2. insert an iron plate (thickrress of about 0.5mm) to the gap
between the choke cover and the corner portion of door
panei as shown figure to free the engagind parts.
,Q ’
1- ‘r FLAT TYPE
SCREK DRIVER
i4
PROTECT BY TAPE
Figure C-4. Latch Head Removal and Door Disassembly
14

DOOR REPLACEMENT
DOOR REPLACEMENT AND ADJUSTMENT
DOOR ADJUSTMENT
1. Disconnect the oven from the power supply and remove the
outer case.
2. Discharge the high voltage capacitor.
3. Remove the four (4) screws holding the upper and lower
oven hinge to the oven cavity. The lower oven hinge is
now free.
4. Remove the door assembly with upper oven hinge by
pull It forward.
When removing and/or loosening hinge such as in the case of a
door replacement, the foilowing adjustment criteria are taken.
Door is adjusted to meet the following three conditions by
keeping screws of hinge loose.
1. Adjust door latch head at a position where they smoothly
catch the latch hook through the latch hole. Refer to latch
switch adjustment.
5. Separate the door assembly and upper oven hinge. The
door assembly IS now free.
6. Re-installlng the upper oven hinge to the new door as-
sembiy.
2. Deviation of the door alignment from the horizontal line
of the cavity face plate is to be less than 1.Omm.
3. The door is positioned with its face depressed toward the
cavity face plate.
7. On re-installing the new door assembly, secure the door
assembly with the four (4) mounting screws to the oven
cavity.
4. Reinstall the outer case and check the mlcrowave leakage
around the door with an approved microwave survey meter.
(Refer to Microwave Measurement Procedure.)
Make sure the door IS parallel with bottom line of the
oven face plate and the latch head pass through the latch
holes correctly.
Note: After any service to the door, and approved mlcrowave
survey meter should be used to assure ln compliance
with proper mlcrowave radlatlon standards.
(Refer to Microwave Measurment Procedure.\
R -6280
,,-*
,y’/ /
RE-INSTALL
\ c
1 i
I/;”
DOOR ASSEMBLY /
CASE
CABINET
Figure C-4. Door Assembly Replacement and Adjustment
15

R -6280
MICRQWAVE MEASUREMENT
After the adjustment of the door latch switches, moni-
tor switch and door are completed individually or col-
lectively, the following leakage test must be performed
with a survey instrument and it must be confirmed that
the result meets the requirements of the performance
standard for microwave oven.
REQUIREMENT
The safety switch must prevent microwave radiation
emission in excess of 5mW/cm2 at any point 5cm or
more from external surface of the oven.
PREPARATION FOR THE TESTING:
Before beginning the actual test for leakage, proceed
as follows;
1. Make sure that test instrument is operating normally
as specified in its instruction booklet.
important:
Survey instruments that comply with the require-
ment for instrumentations as prescribed by the per-
formance standard for microwave ovens must be
used for testing.
Recommended instruments are:
NARDA 8100
NAR DA 8200
HOLADAY HI 1500
SIMPSON 380M
2. Place the oven tray into the oven cavity.
3. Place the load of 275 fl5ml of water initially at
20 +5 “C in the center of the oven tray. The water
container should be a low form of 600 ml beaker
with inside diameter of approx. 8.5cm and made of
an electrically non-conductive material such as
glass or plastic.
The placing of this standard load in the oven is im-
portant not only to protect the oven, but also to in-
sure that any leakage is measured accurately.
4. Close the door and turn the oven ON with the timer
set for several minutes. If the water begins to boil
before the survey is completed, replace it with
275ml of the cool water.
5. Move the probe slowly (not faster that 2.5cm/sec.)
along the gap.
6. The microwave radiation emission should be meas-
ured at any point of 5cm or more from the external
surface of the oven.
.
16

R-6280
C
F
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1 2 3 4 5 6
1
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TTM
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24
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1 2 3 4 / 5 6

R-6280
PARTS LIST
Note : The voltage supplied to the parts “+” are greater than 250V.
REF. NO. PART NO. DESCRIPTION / Q’TY 1 CODE
ELECTRIC PARTS
C
Dl
D2
F
OL
VM
FM
TTM
MG
SW1
SW2
SW3
T
TF
TM
I- 1
l- 2
I- 3
I 2- 1
i2- 2
12 3
i;: ;
i? -
,L- 0
I? -7
,-- J
?
( L- 8
i r.
!i- 9
‘ri AA
j L- tt.d
‘:
j?-. ,
- q*
I .-- 14
/h 4-l
,i-Ii
I - . -3
iL 3
- ,
& L
, z-:5
L- 16
RC- QZAO34WREO
RH- DZAOO8WREO
RH- DZAOl 2WRE0
QFS- COO1 9WREO
RLMPTOOI 8WRE0
QSWTEO235WREO
RMOTEAO42WREO
RMOTDAO33WREO
RV- MZAO34WREO
QSW- MAOO7WREO
QSW- MAO1 OWREO
QSW- MAOO9WREO
RTRN- Al 07WREO
QFS- TAOO4WREO
QSWTEAO31 WREO
QACCAAOI 1 WREO
QSOCLAOOl WREO
QFSHDAOO2WREO
GCABUAI OOWRPO Outer case cabinet
TMAPCA237WRRO Schematic diagram
GDAI AO47WRWO Unit cnass~s
GLEGP002” WREO Foot
LSTPPOO65WRFO Cord anchorage (upper)
iSTPPOO66WRFO Cord anchorage (lower)
PfUSUO455WRPO Shading cushion
“SPAGQOG2YBEO L’iora!!or proof cushion
-ENDKAOi 5WRW0 Capa: :o’ hcider
FD LC- ,q* ~Li&F(FC Far cLJc:
E c i\Nd 40: :, WRKO Fan b aae
-s 7 L’ 0 (? 3 C n/R E 0 car :e:alne: c’ic
“ZiPtiOC;3CWREC~ Cabire- cao
“-‘ZK- /qC’22\r\iFFO ia:cp 13ok
‘\J’!L E \ p i, ;~ 6 2 mlp F 0 CooA FLzi;c!- ‘ever
:t,(s D R C Q 0 L : Wr” E 0 Cook ~:\)LI:c!-, lever sprrng
= f: 2 ‘\’ !=A ; ’ L CZ/RE 0 Caoac :ci’ coVer
Htgh voltage capacrtor
Rectrfrer
Short protector
Fuse M6.3
Oven lamp
Van-motor
Fan motor
Turntable motor
Magnetron
Cook( iower latch) switch (V-5230D)
Upper latch swatch (V-5210D)
Monrtor switch (V-5220D)
Power transformer
Temp. fuse
Timer
Mains supply cord
Lamp socket
CABINET PARTS
CON-I-RQL PANEL PARTS
TI
I
fi
I
I
j
I
!
I
I
I
I
1 AX
1 AK
1 AQ
1 AE
1 AN
1 AX
1 AV
1 AS
1 BM
1 AF
1 AF
1 AF
1 BP
2 AG
1 AY
1 AN
1 AH
1 AE
1
1
1
4
1
1
1
*
I
*I
1
?
7
1
I
1 !
I
i
AV
AC
- A?
4B
A4
4A 1
AA I
A.4 j
L,D :
SG
&;E I
&A 1
t/L+ /
AH j
&D !
44 I
4L j
I i
i3- i 1 H P N L C A 2 9 5 WR R 0 I Contra pane’ frame j 1 1 r\Q i
3- 2
3. 3
2. 4
3- 5
3- 6
3- 7
FKNBKAO92WRKO
FKNBKkO93WRKO
J ETr\;- &248WUFO
.,: 8 T N - A 2 A 7 WR F 0
MSFRPAC34WREO
PTPEHAC2OWREC
Time- r,rob
Varrabfe cooking control knob
Start b~:ror
Open oLt:or
Buttor sprrng
Confro Dane tape
1 1
I 7
j ;
/ 1
1
AF
4F
A3
AF
46
44
A- 1 DOVN- A091 WRTO Over cavity
A- IA LANGFAO5AWRWO Chassis support
4- 18 LANGFAO53WRPO Oven supportrng plate
4- 2 PPACGAOI 7WRE0 O-ring
4- 3 PCUSUA081 WRPO Cushier
4- 4 GCOVHAO? 5 WRWO Turntable motor cover
4- 5 MHNG- AO73WRMO Upper over hinge
4- 6 FHNG- A041 WRMO Lower oven hinge
4- 7 NTNT- AOO7WREO Turntable tray
4- 8 FROLPAOI OWRKO Turntable roller assembly
4- 8A NROLPAOl 2WRE0 Turntabie roller
4- 9 NCPL- A01 5WRF0 Turntable couprrng
4-10 PFI LWAO21 WRPO Oven lamp filter
4-11 PCOVPAO9OWREO Wave gurde cover
4-12 PCLI COO26WREO CllP
4-7 3 PDUC- Al 33WRF0 Steam duct
OVEN PARTS
51
4D
&E
48
AA
AF
AD
AF
AS
AH
AC
AD
AB
AE
AA
AK
18