Sharp R-211A User manual

R-211A
TABLE OF CONTENTS Page
CAUTION, MICROWAVE RADIATION .............................................................................................................. 1
WARNING............................................................................................................................................................1
PRODUCT SPECIFICATIONS........................................................................................................................... 2
GENERAL INFORMATION ................................................................................................................................. 2
APPEARANCE VIEW......................................................................................................................................... 3
OPERATION SEQUENCE ................................................................................................................................. 4
FUNCTION OF IMPORTANT COMPONENTS ................................................................................................... 5
SERVICING ........................................................................................................................................................ 6
TEST PROCEDURE .......................................................................................................................................... 8
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE............................................................. 13
MICROWAVE MEASUREMENT ...................................................................................................................... 19
WIRING DIAGRAM .......................................................................................................................................... 20
PICTORIAL DIAGRAM..................................................................................................................................... 21
PARTS LIST...................................................................................................................................................... 22
In interests of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
MODEL R-211A
S5709R211APX/
MICROWAVE OVEN
SHARP CORPORATION
SERVICE MANUAL
OPEN DOOR
COOKING CONTROL
TIMER
0
5
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25 10
15
0.5 kg
30
1 kg

DEFROST (Kg)
M
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R-211A

R-211A
1
SERVICE MANUAL
SHARP CORPORATION
OSAKA, JAPAN
MICROWAVE OVEN
R-211A
GENERAL IMPORTANT INFORMATION
ThisManualhasbeenpreparedtoprovideSharpCorp.Service
engineers with Operation and Service Information.
It is recommended that service engineers carefully study the
entire text of this manual, so they will be qualified to render
satisfactory customer service.
CAUTION
MICROWAVE RADIATION
DO NOT BECOME EXPOSED TO RADIATION FROM
THE MICROWAVE GENERATOR OR OTHER PARTS
CONDUCTING MICROWAVE ENERGY.
Serviceengineersshouldnotbeexposedtothemicrowave
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.
WARNING
Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is not any other visible damage with the oven.
Servicing and repair work must be carried out only by trained
service engineers.
Allthepartsmarked"★"onpartslistareusedatvoltagesmore
than 250V.
Removal of the outer wrap gives access to potential above
250V.
All the parts marked "∆" on parts list may cause undue
microwave exposure, by themselves, or when they are dam-
aged, loosened or removed.
TEST PROCEDURE
SERVICING AND
TROUBLESHOOTING CHART
FUNCTION OF IMPORTANT
COMPONENTS
OPERATING SEQUENCE
APPEARANCE VIEW
WIRING DIAGRAM
PARTS LIST
COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE
MICROWAVE MEASUREMENT
PRODUCT SPECIFICATIONS

2
R-211A
PRODUCT DESCRIPTION
SPECIFICATION
ITEM DESCRIPTION
Power Requirements 220 Volts
50 Hertz
Single phase, 3 wire earthed
Power Consumption 1.06 KW
Power Output 700 watts nominal of RF microwave energy (IEC-705-1988)
Operating fequency 2450 MHz
Case Dimensions Width 450 mm
Height 295 mm including foot
Depth 357 mm
Cooking Cavity Dimensions Width 285 mm
Height 178 mm
Depth 316 mm
Turntable diameter 272mm
Control Complement 30 min. Single Speed Timer.
Microwave Power for Variable Cooking
Repetition Rate;
HIGH .................................. Full power throughout the cooking time
MEDIUM / DEFROST......................... approx. 45% of FULL Power
Set Weight (Approx.) Approx. 14 kg
GENERAL INFORMATION
WARNING
THIS APPLIANCE MUST BE EARTHED
IMPORTANT
THE WIRES IN THIS MAINS LEAD ARE COLOURED IN ACCORDANCE WITH THE FOLLOWING CODE:
GREEN-AND-YELLOW : EARTH
BLUE : NEUTRAL
BROWN : LIVE

R-211A
3
APPEARANCE VIEW
OVEN
6. Coupling
7. Control panel
8. Door lock openings
9. Ventilation openings
1. Power supply cord
2. Oven lamp
3. Door hinges
4. Safety door latches
5. Door
32
456
7
8
19
COOKING CONTROL
TIMER
OPEN DOOR
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25 10
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0.5kg
30
1kg


DEFROST(Kg)
M
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VARIABLE COOKING CONTROL
There are power levels. The approximate
percentage of microwave power for each 
setting is:

HIGH 100%
MEDIUM/DEFROST 45%
TIMER (0 - 30 min.)
Turn to set cooking time.
DOOR OPEN BUTTON
COOKING CONTROL
TIMER
OPEN DOOR
0
5
20
25 10
15
0.5 kg
30
1 kg


DEFROST (Kg)
M
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MEAT DEFROST GUIDE
(Inner scale)
CONTROLPANEL

4
R-211A
OPERATION SEQUENCE
cycle of a cooking program, the 1st latch switch and
2ndlatchswitchmustopentheir(COM-NO)contacts
first. After that the contacts (COM-NC) of the monitor
switch can be closed.
7-2. When the oven door is closed. The contacts (COM-
NC) of the monitor switch must be opened and the
contacts (COM-NO) of the 2nd latch switch and the
1st latch switch must be closed.
7-3. When the oven door is opened and the (COM-NO)
contacts of the 1st latch switch and the contacts
(COM-NO)ofthe2nd latch switch remain closed,the
fuseM6.3Awillblow,themonitorswitchisclosedand
a short circuit is caused.
HIGH, MEDIUM / DEFROST COOKING
When the microwave oven is preset for variable cooking
power, the rated voltage is supplied to the power trans-
formerintermittentlywithina30-secondtimebasethrough
the vari switch. The following levels of microwave power
are given.
SETTING
HIGH Approx. 100%
Approx. 45%
30 sec. ON
MEDIUM DEFROST
13.5 sec. ON 16.5 sec. OFF
Note: The ON/OFF time ratio does not exactly corre-
spond to the percentage of microwave power,
because approx. 2 seconds are needed for heat-
ing up the magnetron filament.
OFF CONDITION
1. When the timer knob is at " 0 ", the oven is OFF
condition.
2. Closingtheovendooractivatesthe1stlatchswitch,the
2nd latch switch and monitor switch.
IMPORTANT:
When the oven door is closed, the contacts COM-NC of
the monitor switch must be open.
Figure O-1 on page 20
MICROWAVE COOKING CONDITION
HIGH COOKING
Set the variable cooking control to HIGH and then set the
timer.
Function sequence
Figure O-2 on page 20
1. Following components are energized.
Power transformer H.V. capacitor Timer motor
Magnetron H.V. rectifier Fan motor
Turntable motor Oven lamp
2. Ratedvoltage issuppliedto the primarywindingof the
power transformer. The voltage is converted to about
3.3 volts A.C. output on the filament winding and high
voltage of approximately 2000 volts A.C. on the sec-
ondary winding.
3. The filament winding voltage (3.3 volts) heats the
magnetronfilamentandthehighvoltage(2000volts)is
sent to the voltagedoubling circuit, where it is doubled
to negative voltage of approximately 4000 volts D.C..
4. The 2450 MHz microwave energy produced in the
magnetron generates a wave length of 12.24 cm. This
energyischannelledthroughthewaveguide(transport
channel)intothe oven cavity,wherethefoodisplaced
to be cooked.
5. When the cooking time is up, the timer returns to "0",
thebellringsandthe contacts of the timer areopened.
Then following components are turned off.
Power transformer Magnetron Timer motor
Turntable motor H.V. capacitor Fan motor
H.V. rectifier Oven lamp
6. Whentheoven door isopenedduringacookingcycle,
the switches come to the following positions and they
are common to the other cooking conditions too.
Switch Contact Condition
During Oven Door
Cooking Open(No cooking)
1st latch Switch COM-NO Closed Opened
Monitor Switch COM-NC Opened Closed
2nd latch switch COM-NO Closed Opened
The circuit to the power transformer, turntable motor,
timer motor, fan motor and oven lamp are cut off when
the COM-NO contacts of the 2nd latch switch and 1st
latchswitcharemadeopen.Thetimerstopstoindicate
how much cooking time remains.
7. MONITOR SWITCH CIRCUIT
The monitor switch is mechanically controlled by the
oven door, and monitors the operation of the 1st latch
switch and 2nd latch switch.
7-1. When the oven door is opened during or after the

R-211A
5
FUNCTION OF IMPORTANT COMPONENTS
DOOR OPEN MECHANISM
The door is opened by pushing the open button on the
control panel, refer to the Figure D-1.
When the open button is pushed, the open button pushes
theswitchleverupandinturnthelatchheadsarereleased
from latch hook. When the latch heads are released, the
switch lever returns to its original position by its own
weight.
LATCH HOOK
LATCH
HEADS
DOOR
MONITOR SWITCH
1 ST. LATCH
SWITCH
SWITCH LEVER
2ND. LATCH
SWITCH
Figure D-1. Door Open Mechanism
1ST.LATCH SWITCH AND2ND.LATCHSWITCH
1. Whentheovendoorisclosed,thecontacts(COM-NO)
must be closed.
2. When the oven door is opened, the contacts (COM-
NO) must be opened.
MONITOR SWITCH
1. Whentheovendoorisclosed,thecontacts(COM-NC)
must be opened.
2. When the oven door is opened, the contacts (COM-
NC) must be closed.
3. Iftheovendoorisopenedandthecontacts(COM-NO)
ofthe1stlatchswitchand 2nd latchswitchfailtoopen,
the fuse blows simultaneously with closing the con-
tacts (COM-NC) of the monitor switch.
CAUTION: BEFORE REPLACING A FUSE F TEST
THE1STLATCHSWITCHSW1,2NDLATCH
SWITCH, MONITOR SWITCH AND MONI-
TORRESISTOR R FORPROPEROPERA-
TION. (REFER TO CHAPTER "TEST PRO-
CEDURE".)
MONITOR RESISTOR 0.8Ω20W
The monitor resistor prevents the fuse F bursting when
the fuse blows due to the operation of the monitor
switch.
FUSE
1. Thefuseblowswhenthecontacts(COM-NO)ofthe1st
latch switch and 2nd latch switch remain closed with
the oven door open and when the monitor switch
closes.
2. If the wire harness or electrical components are short-
circuited,thefuseblowstopreventanelectricshockof
fire hazard.
TEMPEATURE FUSE 120˚C (OVEN)
The temp. fuse located on the top of the oven cavity is
designedtopreventdamage totheovenifthefoodsinthe
oven catch fire due to over heating produced by improper
settingofcooktimeorfailure of controlunit.Undernormal
operation,thetemp.fuseremainsclosed.However,when
abnormally high temperatures are reached within the
ovencavity,thetemp.fusewillopenat120˚C,causingthe
oven to shut down. The defective fuse must be replaced
with a new one.
THERMAL CUT-OUT 95˚C (MAGNETRON )
The thermal cut-out located on the top of the oven cavity
isdesignedtopreventdamagetothemagnetronifanover
heated condition develops in the tube due to cooling fan
failure,obstructedairguide,dirtyorblockedairintake,etc.
Under normal operation, the thermal cut-out remains
closed.However,whenabnormallyhightemperaturesare
reached within the magnetron, the thermal cut-out will
open at 95˚C, causing the oven to shut down. When the
magnetron has cooled to 75˚, the thermal cut-out closes
and cook cycle will resume.
TURNTABLE MOTOR
The turntable motor drives the roller stay to rotate the
turntable.
FAN MOTOR
Thefanmotordrivesabladewhichdrawsexternalcoolair.
Thiscool air isdirectedthroughthe air vanessurrounding
the magnetron and cools the magnetron. This air is chan-
nelled through the oven cavity to remove steam and
vapours given off from the heating foods. It is then ex-
hausted through the exhausting air vents at the oven
cavity.
TIMER MOTOR (WITH VARI-SWITCH)
Timer switch
1. Whenthetimerisat"0"position,theswitchofthetimer
are opened.
2. When the timer is turned clockwise from "0" position,
the switch of the timer are closed.
Vari-switch
If the variable cooking control is set at HIGH or ME-
DIUM DEFROST, cooking position, Rated voltage is
supplied to the power transformer intermittently within
a 30 seconds time base. The following chart shows the
vari-switch operation in the various modes.
are given.
SETTING
HIGH Approx. 100%
Approx. 45%
30 sec. ON
MEDIUM DEFROST
13.5 sec. ON 16.5 sec. OFF
Note: The ON/OFF time ratio does not exactly corre-
spond to the percentage of microwave power,
because approx. 2 seconds are needed for heat-
ing up the magnetron filament.

6
R-211A
SERVICING
REMEMBER TO CHECK 4R
1) Reconnect all leads removed from components
during testing.
2) Replace the outer case (cabinet).
3) Reconnect the supply.
4) Run the oven. Check all functions.
Microwave ovens should not be run empty. To test for
thepresenceofmicrowaveenergywithinacavity,place
acupofcoldwaterontheoventurntable,closethedoor
andsetthepowerleveltoHIGH.Andsetthemicrowave
timer for two (2) minutes. When the two minutes has
elapsed (timer at zero) carefully check that the water is
now hot. If the water remains cold carry out 3D checks
and re-examine the connections to the component
being tested.
REMEMBER TO CHECK 3D
1) Disconnect the supply.
2) Door opened, and wedged open.
3) Discharge 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
switchedoff.Waitfor60secondsandthenshort-
circuittheconnectionofthehigh-voltagecapaci-
tor (that is, of the connecting lead of the high-
voltagerectifier)againstthechassiswiththeuse
of an insulated screwdriver.
Sharp recommend that wherever possible fault-finding
is carried out with the supply disconnected. It may in,
some cases, be necessary to connect the supply after
theoutercasehasbeenremoved,inthiseventcarryout
3Dchecksandthendisconnecttheleadstotheprimary
of the power transformer. Ensure that these leads
remain isolated from other components and the oven
chassis. (Use insulation tape if necessary.) When the
testingiscompletedcarryout3Dchecksandreconnect
the leads to the primary of the power transformer.
Whenallserviceworkiscompleted,andtheovenisfullyassembled,themicrowavepoweroutputshouldbechecked
and microwave leakage test carried out.
When troubleshooting the microwave oven, it is helpful to
follow the Sequence of Operation in performing the
checks.Manyofthepossiblecausesoftroublewillrequire
that a specific test be performed. These tests are given a
procedureletterwhichwillbefoundinthe"TestProcedure
"section.
TROUBLESHOOTING GUIDE
IMPORTANT: If the oven becomes inoperative because
of a blown fuse M6.3A in the 1st. latch
switch - 2nd. latch switch - monitor switch
- monitor resistor circuit, check the 1st.
latch switch, 2nd. latch switch, monitor
switchand monitorresistorbeforereplac-
ing the fuse M6.3A.
WARNINGTO SERVICE PERSONNEL
Microwaveovenscontaincircuitrycapableofproducingveryhighvoltageandcurrent.Contactwithfollowingparts
will result in electrocution.
High voltage capacitor, Power transformer, Magnetron, High voltage rectifier assembly, High voltage harness.

R-211A
7
TROUBLESHOOTING CHART
PROBLEM
Fuse M6.3Ablowswhenpower
cord is plugged into wall outlet.
Fuse M6.3A blows when
the door is opened.
Home fuse blows when
power cord is plugged into
wall outlet.
Ovendoesnotoperateatall.
Oven goes into cook cycle
butshutsdownbeforeendof
cooking cycle.
Oven lamp does not light.
(Fan motor rotates)
Fanmotordoesnotoperate,
but oven lamp lights.
Timer motor does not oper-
ate, but oven lamp lights.
Turntablemotordoesnotop-
erate, but oven lamp lights.
Ovenseemstobeoperating
but little or no heat is pro-
duced in oven load. (Micro-
wave power control is set at
"HIGH" position, and turnta-
ble motor operates.)
Ovendoesnotoperateprop-
erly in another position ex-
cept "HIGH" position.
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
TEST PROCEDURE
OFF
CONDITION
CONDITION
MAGNETRON POWER TRANSFORMER H.V. RECTIFIER ASSEMBLY HIGH VOLTAGE CAPACITOR 1ST. LATCH SWITCH
2ND. LATCH SWITCH MONITOR SWITCH TEMPERATURE FUSE 120˚C (OVEN) THERMAL CUT-OUT 95˚C (MG) TIMER MOTOR
TIMER CONTACT TIMER DEFROST SWITCH FAN MOTOR TURNTABLE MOTOR FUSE M6.3A
POWER SUPPLY CORD SHORTED WIRE HARNESS OPENED WIRE HARNESS OVEN LAMP OR SOCKET BLOCKED VENTILATION OPENING
MISADJUSTMENT SWITCH HOME FUSE OR BREAKER WALL OUTLET BLOCKED COOLING FAN
POWER SELECT SWITCH
ABCDEEEGGJ J JHH I E
COOKING
CONDITION

8
R-211A
CARRY OUT 3D CHECKS.
Isolate the magnetron from the high voltage circuit by removing all leads connected to the filament
terminal.
Totestforanopencircuitfilamentuseanohmmetertomakeacontinuitytestbetweenthemagnetron
filament terminals, the meter should show a reading of less than 1 ohm.
Totestfora short circuit filament toanodecondition,connectohmmeterbetweenoneofthefilament
terminalsandthecaseofthemagnetron(ground).Thistestshouldbeindicatedaninfiniteresistance.
If a low or zero resistance reading is obtained then the magnetron should be replaced.
MICROWAVE OUTPUT POWER (IEC705)
The following test procedure should be carried out with the microwave oven in a fully assembled
condition (outer case fitted). Microwave output power from the magnetron can be measured by way
of IEC 705, i.e. it can be measured by using water load how much it can be absorbed by the water
load.Tomeasurethemicrowaveoutputpowerinthemicrowaveoven,therelationofcalorieandwatt
is used. When P(W) heating works for t(second), approximately P x t/4.187 calorie is generated. On
theotherhand,ifthe temperature of the water withV(ml)rises∆T(˚C)duringthismicrowaveheating
period, the calorie of the water is V x ∆T.
Measuring condition:
1. Container
The water container must be a cylindrical borosilicate glass vessel having a maximum material
thickness of 3 mm and an outside diameter of approximately 190 mm.
2. Temperature of the oven and vessel
The oven and the empty vessel are at ambient temperature prior to the start of the test.
3. Temperature of the water
The initial temperature of the water is (10±2)˚C.
4. Select the initial and final water temperature so that the maximum difference between the final
water temperature and the ambient temperature is 5˚C.
5. Selectstirringdevicesandmeasuringinstrumentsinordertominimizeadditionorremovalofheat.
6. The graduation of the thermometer must be scaled by 0.1˚C at minimum and an accurate
thermometer.
7. The water load must be (1000±5) g.
8. “t”ismeasuredwhilethemicrowavegeneratorisoperatingatfullpower.Magnetronfilamentheat-
up time is not included.
NOTE: The operation time of the microwave oven is “t + 2” sec. 2 sec. is magnetron filament heat-
up time.
Measuring method:
1. Measure the initial temperature of the water before the water is added to the vessel.
(Example: The initial temperature T1 = 11˚C)
2. Add the 1 litre water to the vessel.
3. Place the load on the centre of the shelf.
4. Operate the microwave oven at HIGH for the temperature of the water rises by a value ∆T of
(10 ±2)˚C.
5. Stir the water to equalize temperature throughout the vessel.
6. Measure the final water temperature. (Example: The final temperature T2 = 21°C)
7. Calculate the microwave power output P in watts from above formula.
NEVERTOUCHANYPARTINTHECIRCUITWITHYOURHANDORANINSULATEDTOOL
WHILE THE OVEN IS IN OPERATION.
The formula is as follows;
P x t / 4.187 = V x ∆T P (W) = 4.187 x V x ∆T / t
Our condition for water load is as follows:
Room temperature..............around 20˚C Power supply Voltage.........Rated voltage
Water load.........1000 g Initial temperature...........10±2°C Heating time.........60 sec.
P = 70 x ∆T
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
A MAGNETRON TEST

R-211A
9
1000g
1000g
1000g
T1˚C T2˚C
Heat up for 62 sec.
B POWER TRANSFORMER TEST
CARRY OUT 3D CHECKS.
Disconnect the leads to the primary winding of the power transformer. Disconnect the filament and
secondary winding connections from the rest of the HV circuitry. Using an ohmmeter, set on a low
range, it is possible to check the continuity of all three windings. The following readings should be
obtained:
WARNING: High voltages and large currents are present at the secondary winding and
filament winding of the power transformer. It is very dangerous to work near this
part when the oven is on. NEVER make any voltage measurements of the high-
voltage circuits, including the magnetron filament.
If the reading obtained are not stated as above, then the power transformer is probably faulty and
should be replaced.
CARRY OUT 4R CHECKS.
Initial temperature.................................................................................................. T1 = 11°C
Temperature after (60 + 2) = 62 sec...................................................................... T2 = 21°C
Temperature difference Cold-Warm .................................................................... ∆T1 = 10°C
Measured output power
The equation is “P = 70 x ∆T”....................................................... P = 70 x 10°C = 700 Watts
JUDGMENT: The measured output power should be at least ±15 % of the rated output power.
CAUTION: 1°C CORRESPONDS TO 70 WATTS. REPEAT MEASUREMENT IF THE POWER IS
INSUFFICIENT.
a.Primary winding................1.9 ohms approximately
b.Secondary winding ...........162 ohms approximately
c.Filament winding ..............less than 1 ohm
C HIGH VOLTAGE RECTIFIER ASSEMBLY TEST
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
HIGH VOLTAGE RECTIFIER TEST
CARRY OUT 3D CHECKS.
IsolatethehighvoltagerectifierassemblyfromtheHVcircuit.Thehighvoltagerectifier canbetested
using an ohmmeter set to its highest range. Connect the ohmmeter across the terminal B+C of the
high voltage rectifier and note the reading obtained. Reverse the meter leads and note this second
reading.Thenormalresistanceisinfiniteinonedirectionandmorethan100kΩintheotherdirection.
CARRY OUT 4R CHECKS.
NOTE: FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER, THE BATTERIES OF
THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE AT LEAST 6 VOLTS, BE-
CAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE SHOWN IN BOTH DIREC-
TIONS.
BC
HIGH VOLTAGE RECTIFIER

10
R-211A
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
E SWITCH TEST
D HIGH VOLTAGE CAPACITOR TEST
CARRY OUT 3D CHECKS.
A. Isolate the high voltage capacitor from the circuit.
B. Continuity check must be carried out with measuring instrument which is set to the highest
resistance range.
C. A normal capacitor shows continuity for a short time (kick) and then a resistance of about 10MΩ
after it has been charged.
D. A short-circuited capacitor shows continuity all the time.
E. An open capacitor constantly shows a resistance about 10 MΩbecause of its internal 10MΩ
resistance.
F. When the internal wire is opened in the high voltage capacitor shows an infinite resistance.
G. The resistance across all the terminals and the chassis must be infinite when the capacitor is
normal.
If incorrect reading are obtained, the high voltage capacitor must be replaced.
CARRY OUT 4R CHECKS.
Isolate the switch to be tested and using an ohmmeter check between the terminals as described in
the following table.
CARRY OUT 3D CHECKS.
Table: Terminal Connection of Switch
Plunger Operation COM to NO COM to NC
Released Open circuit Short circuit
Depressed Short circuit Open circuit
If incorrect readings are obtained, make the necessary switch adjustment or replace the switch.
CARRY OUT 4R CHECKS.
FMONITOR RESISTOR TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the monitor resist. Using an ohmmeter and set on a low range. Check
between the terminals of the monitor resistor.
The resistance of monitor resistor is approx. 0.8 ohms.
If incorrect readings are obtained, replace the monitor resistor.
CARRY OUT 4R CHECKS.
GTEMPERATURE FUSE OR THERMAL CUT-OUT TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make a
continuity test across the two terminals as described in the below.
CARRY OUT 4R CHECKS.
Table: Temperature Fuse or Thermal Cut-out Test
Temperature of Temperature of Indication of
"ON" condition "OFF" condition ohmmeter
Parts Name (closed circuit). (open circuit). (When room
(˚C) (˚C) temperature is
approx. 20˚C.)
Temp. fuse 120˚C This is not resetable Above 120˚C Closed circuit
type.
Thermal cut-out Below 75˚C Above 95˚C Closed circuit.
COM; Common terminal,
NO; Normally open terminal
NC; Normally close terminal

R-211A
11
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
IFUSE M6.3A
CARRY OUT 3D CHECKS.
If the fuse M6.3A is blown when the door is opened, check the 1st latch switch, 2nd latch switch, monitor
switch and monitor resistor.
IfthefuseM6.3Aisblownbyincorrectdoorswitchingreplacethedefectiveswitch(es)andthefuseM6.3A.
If the fuse M6.3A is blown, there is a shorts or grounds in electrical parts or wire harness.
Check them and replace the defective parts or repair the wire harness.
CARRY OUT 4R CHECKS.
CAUTION: Only replace fuse with the correct value replacement.
If incorrect readings are obtained, replace the temperature fuse or thermal cut-out.
An open circuit thermal cut-out (MG) indicates that the magnetron has overheated, this may be due
to resistricted ventilation, cooling fan failure or a fault condition within the magnetron or HV circuit.
Anopencircuittemperaturefuse(OVEN)indicatesthatthefoodintheovencavitymaycatchfire,this
may be due to overheating produced by improper setting of the cooking time or failure of the control
panel.
HMOTOR WINDING TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals as described in the table below.
Table: Resistance of Motor
Motors Resistance
Fan motor Approximately 330 ohms
Turntable motor Approximately 12 kohms
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
J TIMER MOTOR (WITH DEFROST-SWITCH) TEST
CARRY OUT 3D CHECKS before any of the following timer tests.
TIMER SWITCH- CONTACTS
Disconnect the leads from terminals described at following table. Connect an ohmmeter across
terminals described at following table.
Advance the timer and check that a short circuit reading is obtained on the meter.
Turn the timer back to the zero (0) position and check that an open circuit reading is obtained on the
meter. If these readings are not obtained then replace the timer.
Disconnecting and checking terminals 1 and 4
TIMER - MOTOR
Disconnect the leads from terminals described at following table. Connect an ohmmeter across the
timermotorwinding,terminalsaredescribedatfollowingtable,andcheckthatareadingofresistance
described at following table is indicated.
If this reading is not obtained then the timer is probably defective and should be replaced.
Disconnecting and checking terminals 1 and 2
Resistance of motor winding approximately 22.8 kohms
CARRY OUT 4R CHECKS after any of the above tests.

12
R-211A
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
ON: Meter indicates closed. OFF: Meter indicates open.
Check results: Ifanyoftheconditionasdescribedinthetablearenotobtained,thenthetimershould
be replaced.
CARRY OUT 4R CHECKS.
DEFROST SWITCH - CONTACTS
Before proceeding with this part of the test, check the relay coil as outlined above.
WARNING:This test requires the oven to be operated with supply connected.
Follow the instruction below carefully.
1. CARRY OUT 3D CHECKS.
2. Disconnect the leads to the primary of the power transformer. Make sure that the leads remain
isolated from other oven components and chassis.
3. Disconnect the leads from terminals 1 and 3 of the timer, make sure that these leads remain
isolated from other components and the oven chassis (use insulation tape if necessary). Do not
disconnect leads from terminals 1 and 2.
4. Securelycliptheleadsofanohmmeteracrossterminals1and3ofthetimer.(Makesurethemeter
can be read easily without being touched during the test.)
5. Close the door of the oven.
6. Connect the supply.
7. Set the TIMER to several minutes.
8. Without touching the meter or any part of the oven make a note of the time which the ohmmeter
indicates S.C. and O.C. in each power level as described in the table.
9. Set the MICROWAVE TIMER to 0 (zero).
10.CARRY OUT 3D CHECKS.
11.Disconnect meter from terminals 1 and 3 of the timer.
12.Disconnect meter leads and reconnect the leads to the primary of the power transformer.
VARI-MODE ON TIME OFF TIME
HIGH (approx. 100% power) 30 sec 0 sec.
MEDIUM DEFROST (approx. 45% power) 13.5 sec 16.5 sec.
S.C. = Short circuit O.C. = Open circuit
Timermotorwithdefrostswitch
M
1
42
3
SW1 
(Main Switch)
SW2 
(Defrost Switch)

R-211A
13
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WARNING: Avoid possible exposure to microwave energy. Please follow the instructions
below before operating the oven.
1. Disconnect oven from power supply.
2. Makesurethatadefinite” click”canbeheardwhenthe
microwave oven door is unlatched. (Hold the door in a
closedpositionwithonehand,thenpushthedooropen
buttonwiththeother,thiscausesthelatchleadstorise,
it is then possible to hear a “click’ as the door switches
operate.)
3. Visually check the door and cavity face plate for dam-
age (dents, cracks, signs of arcing etc.).
Carry out any remedial work that is necessary before
operating the oven.
Do not operate the oven if any of the following conditions
exist;
To remove the outer case proceed as follows.
1. Disconnect oven from power supply.
2. Open the oven door and wedge it open.
3. Removethescrews from rearandalongthesideedge
of case.
4. Slide the entire case back about 3cm to free it from
retaining clips on the cavity face plate.
5. Lift the entire case from the oven.
1. Door does not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal or damaged.
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. Therearedefective partsinthemicrowavegenerating
and transmission assembly.
7. There is visible damage to the oven.
Do not operate the oven:
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.
Please refer to ‘OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS’, when carrying out any
of the following removal procedures:
OUTER CASE REMOVAL
6. Discharge the H.V. capacitor before carrying out any
further work.
7. Do not operate the oven with the outer case removed.
N.B.; Step 1, 2 and 6 form the basis of the 3D checks.
CAUTION: DISCHARGEHIGHVOLTAGECAPACITOR
BEFORETOUCHINGANYOVENCOMPO-
NENT OR WIRING.
HIGH VOLTAGE COMPONENTS REMOVAL
(HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY)
To remove the components, proceed as follows.
1. CARRY OUT 3D CHECKS.
2. Removeone(1)screwholdingcapacitorholdertorear
cabinet.
3. DisconnecttheH.V. wire of the H.V.rectifierassembly
from the magnetron.
4. Disconnect the filament lead of the power transformer
from the H.V. capacitor.
5. Remove one (1) screw holding earth side terminal of
high voltage rectifier assembly, and remove capacitor
holder.
6. Disconnect all the leads and terminals of high voltage
rectifier assembly from high voltage capacitor.
7. Disconnect the H.V. wire B from the H.V. capacitor.
8. NowH.V.rectifierassemblyand H.V.capacitorshould
be free.
CAUTION: WHENREPLACINGHIGHVOLTAGEREC-
TIFIER ASSEMBLY, ENSURE THAT THE
CATHODE (EARTH) CONNECTION IS SE-
CURELY FIXED TO THE CAPACITOR
HOLDER WITH AN EARTHING SCREW.
CAUTION: DONOTREPLACEONLYHIGHVOLTAGE
RECTIFIER. WHEN REPLACING IT, RE-
PLACE HIGH VOLTAGE RECTIFIER AS-
SEMBLY.
1. CARRY OUT 3D CHECKS.
2. Disconnectthewireleads(mainwireharnessandH.V.
wire) from power transformer.
3. Disconnect the lead from magnetron filament.
4. Removeone(1)screwholdingcapacitorholdertorear
cabinet.
5. Disconnecttheleadofthepowertransformerfromhigh
voltage capacitor.
6. Remove the two (2) screws holding the transformer to
bottom plate.
7. Remove the transformer.
POWER TRANSFORMER REMOVAL

14
R-211A
CAUTION: WHEN REPLACING THE MAGNETRON,
BE SURE THE R.F. GASKET IS IN PLACE
AND THE MAGNETRON MOUNTING
SCREWS ARE TIGHTENED SECURELY.
MAGNETRON REPLACEMENT
Removal
1. CARRY OUT 3D CHECKS.
2. Disconnect the wire leads from the magnetron.
3. Carefully remove the two (2) screws holding the mag-
netron to the waveguide flange.
4. Lift up magnetron with care so that the magnetron
antennaisnot hit by anymetalobjectaroundantenna.
5. Now, the magnetron is free.
Re-install
1. Re-install the magnetron to the waveguide flange with
two (2) screws diagonally as shown in Figure C-1.
2. Re-connect the wire leads to the magnetron. Refer to
"PICTORIAL DIAGRAM".
3. Re-install the outer case and check that the oven is
operating properly. Figure C-1. Magnetron Replacement
Screws
Magnetron
Wavegiude 
Flange
OVEN LAMP SOCKET REMOVAL
POSITIVE LOCK®CONNECTOR REMOVAL
1. CARRY OUT 3D CHECKS.
2. Pushing the lever of positive lock®connector.
3. Pull out the positive lock®connector.
CAUTION:
When you (Service engineers) connect the positive lock®
connectors to the terminals, connect the positive lock®so
that the lever face you (Service engineers).
1. CARRY OUT 3D CHECKS
2. Pull the wire leads from the oven lamp socket by
pushing the terminal hole of the oven lamp socket
with the flat type small screw driver.
3. Tear the cushion from the light mount plate.
4. Bend the tab of the light mount plate holding the oven.
5. Lift up the oven lamp socket.
6. Now, the oven lamp socket is free. Figure C-2. Oven lamp socket
POWER SUPPLY CORD REPLACEMENT
Removal
1. CARRY OUT 3D CHECKS.
2. Remove the single (1) screw holding the green/yellow
wire to the oven cavity.
3. Disconnect the brown wire of the power supply cord
from the fuse holder.
4. Cut away the connector (CE-230).
5. Releasethemouldingcordstopperofthepowersupply
cordfromthesquareholeoftheovencavitybackplate,
referring to the Figure C-4 (b).
6. Now, the power supply cord is free.
Re-install
1. Insert the moulding cord stopper of power supply cord
intothesquareholeof the rear cabinet, referring tothe
Figure C-4 (b).
2. Install the earth wire lead of power supply cord to the
oven cavity with one (1) screw and tight the screw.
3. Connectthebrownwireofthepowersupplycordtothe
fuseholdercorrectly,referringtothePictorialDiagram.
4. Makesurethatthebluewireleadofmainwireharness
and white wire lead of the power supply cord are
stripped 15mm length from its end .
5. Wind the conductor of the blue and white wires each
other.
6. Insert them into the connector (CE-230). And clamp it.
Oven lamp
socket
Terminal
Wire lead
Terminal hole
Flate type small
screw driver
Terminal
Push
Pull down
1
2
Lever
Positive lock®
connector
Figure C-3 Positive lock®connector

R-211A
15
Figure C-4(a). Power Supply Cord Replacement Figure C-4 (b) Power Supply Cord Replacement
CONTROL PANEL ASSEMBLY AND SWITCH LEVER REMOVAL
1. CARRY OUT 3D CHECKS.
2. Disconnect the leads from the timer motor.
3. Removetheone(1)screwholdingthechassissupport
to the front plate of the oven cavity.
4. Remove the chassis support from the oven.
5. Lift up the control panel and release it from the oven
cavity.
6. Now, the control panel assembly is free.
7. Openthe door. Remove theswitchleverfromthe front
plate of the oven cavity.
Removal
1. Disconnect the oven from the power supply.
2. Remove the turntable and turntable support from the
oven cavity.
3. Turn the oven over.
4. Cut the four (4) bridges holding the turntable motor
cover to the bottom plate with the cutting pliers as
shown in Figure C-5.
CAUTION: DONOTDROPTHETURNTABLEMOTOR
COVER INTO THE OVEN AFTER CUTTING
THE BRIDGES. BECAUSE IT WILL DAM-
AGE THE WIRE LEADS OF THE MOTOR
AND IT IS DIFFICULT TO REMOVE IT OUT
OF THE OVEN.
5. Remove the turntable motor cover from the bottom
plate.
6. Disconnect the wire leads from the turntable motor.
7. Remove the single (1) screw holding the turntable
motor to the oven cavity.
8. Remove the turntable motor from the oven cavity.
TURNTABLE MOTOR REPLACEMENT
9. Remove the O-ring and washer from the turntable
motor.
10.Now, the turntable motor is free.
Re-install
1. Remove the any sharp edges on the turntable motor
cover and the bottom plate with the cutting pliers.
2. Re-install the O-ring.
3. Apply the grease (Shinetsu silicone grease G-420 of
Sinetsu Chemical Co. Ltd. or Toray Silicone grease
SH-14ofToraySiliconeCo.,Ltd.)totheO-ringandthe
baseoftheturntablemotorshaftasshowninFigureC-
6.
4. Re-install the turntable motor with the O-ring and
washer to the oven cavity with the single (1) screw.
5. Re-connect the wire leads to the turntable motor.
6. Insert the tab of the turntable motor cover into the hole
of the bottom plate as shown in Figure C-5.
7. Re-installtheturntablemotorcovertothebottomplate
with one (1) screw XHTSD40P08RV0 or
XFPSD40P08K00 as shown in Figure C-5.
Cutting pliers
Bridges
Bridges
Turntable motor 
cover
XHTSD40P08RV0
or
XFPSD40P08K00
Tab
Hole
Bottom plate
Screw:
Washer
O-ring
Base of turntable
motor shaft
Turntable motor
O-ring
Washer
Apply grease here
Figure C-5. Turntable Motor Cover Figure C-6. Washer and O-ring Installation and
Grease Applying.
Oven Cavity
Power Supply 
Cord
Brown Wire
Fuse Holder
Blue Wire
Green/ Yellow 
Wire
Square Hole
Moulding 
Cord Stopper
Oven Cavity 
Back Plate
Power Supply
Cord
15 mm Connector CE-230
Blue wire lead of 
power supply cord
Wire lead of the 
main wire harness

16
R-211A
FAN MOTOR REPLACEMENT
REMOVAL
1. CARRY OUT 3D CHECKS.
2. Disconnect the wire leads from the fan motor.
3. Removetheone(1)screwholdingthechassissupport
to the oven cavity front plate.
4. Remove the chassis support .
5. Releasethefilamentleadofthepowertransformerand
the H.V. wire from the fan duct.
6. Remove the one (1) screw holding the fan duct to the
waveguide flange.
7. Release the fan motor assembly from the oven cavity.
8. Removethefanbladefromthefanmotorshaftaccord-
ing to the following procedure.
1) Hold the edge of the rotor of the fan motor by using
a pair of groove joint pliers.
CAUTION:
• Makesurethatanypiecesdonotenterthegap
between the rotor and the stator of the fan
motor.Becausethe rotoriseasyto beshaven
by pliers and metal pieces may be produced.
• Do not touch the pliers to the coil of the fan
motor because the coil may be cut or injured.
• Donottransformthebracketbytouchingwith
the pliers.
2) Remove the fan blade assembly from the shaft of
the fan motor by pulling and rotating the fan blade
with your hand.
3) Now, the fan blade will be free.
CAUTION:
• Do not re-use the removed fan blade be-
cause the hole (for shaft) may be lager
than normal.
9. Remove the two (2) screws holding the fan motor to
the fan duct.
10. Now, the fan motor is free.
INSTALLATION
1. Install the fan motor to the fan duct with the two (2)
screws.
2. Install the fan blade to the fan motor shaft according
the following procedure.
1) Hold the centre of the bracket which supports the
shaft of the fan motor on the flat table.
2) Applythescrewlocktightintothehole(forshaft)ofthe
fan blade.
3) Install the fan blade to the shaft of fan motor by
pushing the fan blade with a small, light weight, ball
peen hammer or rubber mallet.
CAUTION:
• Do not hit the fan blade strongly when installed
because the bracket may be transformed.
• Make sure that the fan blade rotates smooth
after installed.
• Make sure that the axis of the shaft is not
slanted.
3. Install the fan motor assembly to the oven cavity by
fittingtheholesofthefanductintothetabsoftheoven
cavity.
4. Re-install the fan duct to the waveguide flange with
the one (1) screw.
5. Inserttheendofthechassissupportintotheslitofthe
oven cavity rear cabinet.
6. Re-installthe chassis supporttotheoven cavity front
plate with the one (1) screw.
7. InstallthefilamentleadandtheH.V.wireintothehole
of the fan duct .
8. Connect the wire leads to the fan motor, referring to
the pictorial diagram.
Rear View
Gap Rotor
Bracket
Stator
Groove joint pliers
Coil
Shaft
Axis Stator
These are the areas 
that should be held
with a pliers
Rotor
Shaft
Table Center of
bracket
Side View
1ST. LATCH SWITCH, 2 ND. LATCH SWITCH AND MONITOR SWITCH REMOVAL
1. CARRY OUT 3D CHECKS.
2. Disconnect wire leads from all switches.
3. Remove the control panel assembly and switch lever
from the oven cavity front flange. Referring to chapter
"CONTROL PANEL ASSEMBLY AND SWITCH LE-
VER REMOVAL"
4. Remove two (2) screws holding latch hook to oven
flange.
5. Remove latch hook assembly from oven flange.
6. Push outward on the two (2) retaining tabs holding
switch in place.
7. Switch is now free.
Re-install
1. Re-installeachswitchinitsplace.The1st.latchswitch
andmonitorswitchareinupperposition.The2nd.latch
switch is in the lower position.

R-211A
17
2. Re-connectwireleadstoeachswitch.Refertochapter
"Pictorial Diagram".
3. Secure latch hook (with two (2) mounting screws) to
oven flange.
4. Re-install the switch lever and the control panel as-
sembly to the oven cavity front flange.
5. Re-connect wire leads to the timer motor. Refer to
chapter "Pictorial Diagram".
6. Make sure that monitor switch is operating properly
and check continuity of the monitor circuit. Refer to
chapter "Test Procedure", and Adjustment Procedure
below.
1ST. LATCH SWITCH, 2ND. LATCH SWITCH AND MONITOR SWITCH ADJUSTMENT
Ifthe1st.latchswitch,2nd.latchswitchandmonitorswitch
do not operate properly due to a misadjustment, the
following adjustment should be made.
1. Loosenthetwo(2)screwsholdingthelatchhooktothe
flange of the oven front face.
2. With the door closed, adjust latch hook by moving it
back and forth and up and down. In and out play of the
door allowed by the upper and lower position of the
latch hook should be less than 0.5mm. The horizontal
positionofthelatchhookshouldbeadjustedsothatthe
monitor switch is activated with the door closed. The
verticalpositionofthelatchhookshouldbeadjustedso
that the 1st. latch switch and the 2nd. latch switch are
activated with the door closed.
3. Secure the screws firmly.
4. Check the operation of all switches. If each switch has
not activated with the door closed, loosen screw and
adjust the latch hook position.
After adjustment, make sure of the following.
1. In and out play of the door remains less than 0.5mm
wheninthelatchedposition.Firstcheckupperposition
oflatchhook,pushingandpullingupperportionofdoor
toward the oven face. Then check lower portion of the
latch hook, pushing and pulling lower portion of door
toward the oven face. Both results (play in the door)
should be less than 0.5mm.
2. The1st.latchswitchand2nd.latchswitchinterruptthe
circuit before the door can be opened.
3. The monitor switch contacts close when the door is
opened.
4. Re-installoutercaseandcheckformicrowaveleakage
around the door with an approved microwave survey
meter.(RefertoMicrowaveMeasurementProcedure.)
LATCH HOOK
LATCH
HEADS
DOOR
MONITOR SWITCH
1 ST. LATCH
SWITCH
SWITCH LEVER
2ND. LATCH
SWITCH
Figure C-7. Latch Switch Adjustments
DOOR REPLACEMENT
7. Release two (2) pins of door panel from two (2) hole of
upper and lower oven hinges by lifting up.
8. Now, door panel is free from oven cavity.
9. Release door panel from ten (10) tabs of door frame
and remove door frame by sliding the door panel
downward.
10.Now, door panel with sealer film is free.
11.Tear sealer film from door panel.
12.Now, door panel is free.
13.Slidelatchheadupwardandremoveitfromdoorframe
with releasing latch spring from door frame and latch
head.
14.Now, latch head and latch spring are free.
15.Remove door screen from door frame.
16.Now, door screen is free.
RE-INSTALL
1. Re-install door screen to door frame.
2. Re-install latch spring to the head. Re-install latch
spring to the door frame. Re-install latch head to the
door frame.
3. Re-install door panel to door frame by fitting ten (10)
tabs of door frame to ten (10) holes of door panel.
4. Put sealer film on door panel. Refer to "Sealer Film"
REMOVAL
1. Disconnect oven from power supply.
2. Push the open button and open the door slightly.
3. Insertaputty knife (thicknessofabout0.5mm)intothe
gap between the choke cover and corner portion of
door panel as shown in Figure C-8 to free engaging
parts.
4. Trytheprinciplesoftheleverandliftupthechokecover
by inserting a putty knife in order shown in figure C-8.
5. Release choke cover from door panel.
6. Now choke cover is free.
Putty Knife
Choke Cover
1
2
3
4
5
67
8
910 11 12
Door Panel
Figure C-8. Door Disassembly

18
R-211A
and figure C-10, on how to handle the new film.
5. Catchtwo(2)pinsofdoorpanelontwo(2)holeofupper
and lower oven hinges.
6. Re-install choke cover to door panel by pushing.
Note: After any service to the door;
(A) Makesurethat1st.latchswitch,2nd.latchswitch
andmonitorswitchareoperatingproperly.(Refer
to chapter "Test Procedures".).
(B) An approved microwave survey meter should be
used to assure compliance with proper micro-
wave radiation emission limitation standards.
After any service, make sure of the following :
1. Door latch heads smoothly catch latch hook through
latch holes and that latch head goes through centre of
latch hole.
2. Deviation of door alignment from horizontal line of
cavity face plate is to be less than 1.0mm.
3. Door is positioned with its face pressed toward cavity
face plate.
4. Check for microwave leakage around door with an
approved microwave survey meter. (Refer to Micro-
wave Measurement Procedure.)
Note: The door on a microwave oven is designed to act
as an electronic seal preventing the leakage of
microwave energy from oven cavity during cook
cycle. This function does not require that door be
air-tight, moisture (condensation)-tight or light-
tight. Therefore, occasional appearance of mois-
ture,lightorsensingofgentlewarmairmovement
around oven door is not abnormal and do not of
themselves, indicate a leakage of microwave en-
ergy from oven cavity.
UPPER 
OVEN HINGE
PIN
DOOR PANEL
CHOKE 
COVER
PIN
LOWER 
OVEN 
HINGE
Figure C-9. Door Replacement
SEALER FILM
Installation
1. Put the adhesive tape on the backing film of the sealer
film as shown in Fig. C-10.
2. Tear the backing film by pulling the adhesive tape.
3. Putthepastedsideofthesealerfilmonthedoorpanel.
Sealer film Backing film
Adhesive tape
Figure C-10. Sealer film