Sharp R-939(BK), R-939(IN), R-939(W) Service Manual

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R939(W)
SERVICE MANUAL
S9614R939PHW/
MICROWAVE OVEN WITH
GRILL AND CONVECTION
CONTENTS
CHAPTER 1. BEFORE SERVICING
CHAPTER 2. WARNING TO SERVICE PERSONNEL
CHAPTER 3. PRODUCT SPECIFICATIONS
CHAPTER 4. APPEARANCE VIEW
CHAPTER 5. OPERATION SEQUENCE
MODELS
R-939(BK) R-939(IN)
R-939(W)
In interests of user-safety the oven should be restored to its original condition and only parts identical to those specified should be used.
CHAPTER 9. TOUCH CONTROL PANEL ASSEMBLY
CHAPTER 10. PRECAUTIONS FOR USING LEAD­FREE SOLDER
CHAPTER 11. COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
CHAPTER 12. MICROWAVE MEASUREMENT
CHAPTER 6. FUNCTION OF IMPORTANT COMPO­NENTS
CHAPTER 7. TROUBLESHOOTING GUIDE
CHAPTER 13. TEST DATA AT A GLANCE
CHAPTER 14. CIRCUIT DIAGRAMS
Parts List
This document has been published to be used for after sales service only. The contents are subject to change without notice.
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CONTENTS
CHAPTER 1. BEFORE SERVICING
[1] GENERAL IMPORTANT INFORMA-
TION ........................................................... 1-1
[2] WARNING................................................... 1-1
[3] CAUTION MICROWAVE RADIATION ........ 1-2
CHAPTER 2. WARNING TO SERVICE PERSON­NEL
CHAPTER 3. PRODUCT SPECIFICATIONS
CHAPTER 4. APPEARANCE VIEW
[1] OVEN.......................................................... 4-1
[2] TOUCH CONTROL PANEL ........................ 4-1
CHAPTER 5. OPERATION SEQUENCE
[1] OFF CONDITION........................................ 5-1
[2] MICROWAVE COOKING CONDITION....... 5-1
[3] GRILL COOKING CONDITION .................. 5-2
[4] CONVECTION COOKING CONDITION..... 5-2
[5] DUAL COOKING CONDITION ................... 5-2
[6] ON/OFF TIME RATIO ................................. 5-3
[7] AUTOMATIC COOKING ............................. 5-3
[8] POWER OUTPUT REDUCTION ................ 5-3
[9] FAN MOTOR OPERATION ......................... 5-3
[10] CONVECTION MOTOR OPERATION........ 5-3
CHAPTER 6. FUNCTION OF IMPORTANT COM­PONENTS
[1] DOOR OPEN MECHANISM ....................... 6-1
[2] MONITORED LATCH SWITCH (SW1) ....... 6-1
[3] STOP SWITCH (SW2)................................ 6-1
[4] MONITOR SWITCH (SW3)......................... 6-1
[5] FUSE (F1) 20A 250V .................................. 6-1
[6] FUSE (F2) F8A 250V (NOISE FILTER) ...... 6-1
[7] TC TRANSFORMER .................................. 6-1
[8] THERMAL CUT-OUT (TC1) 125C (MG)..... 6-1
[9] THERMAL CUT-OUT (TC2) 170C
(GRILL) ....................................................... 6-1
[10] THERMAL CUT-OUT (TC3) 170C
(CONV.)....................................................... 6-1
[11] ASYMMETRIC RECTIFIER........................ 6-1
[12] NOISE FILTER............................................ 6-2
[13] TURNTABLE MOTOR (TTM)...................... 6-2
[14] FAN MOTOR (FM) ...................................... 6-2
[15] CONVECTION MOTOR (CM)..................... 6-2
[16] GRILL HEATING ELEMENT (GH) .............. 6-2
[17] CONVECTION HEATING ELEMENT
(CH) ............................................................ 6-2
[18] CONVECTION COOKING SYSTEM .......... 6-2
[19] FIRE SENSING FEATURE ......................... 6-2
[20] OPEN JUDGE BY THERMISTOR .............. 6-2
[21] DAMPER OPEN-CLOSE MECHANISM..... 6-2
CHAPTER 7. TROUBLESHOOTING GUIDE
[1] FOREWORD............................................... 7-1
[2] CHART........................................................ 7-2
CHAPTER 8. TEST PROCEDURES
[1] Procedure A: MAGNETRON TEST ............ 8-1
[2] Procedure B: HIGH VOLTAGE TRANS-
FORMER TEST .......................................... 8-2
[3] Procedure C: HIGH VOLTAGE RECTIFI-
ER TEST..................................................... 8-2
[4] Procedure D: HIGH VOLTAGE CAPACI-
TOR TEST .................................................. 8-2
[5] Procedure E: SWITCH TEST...................... 8-3
[6] Procedure F: THERMISTOR TEST ............ 8-3
[7] Procedure G: THERMAL CUT-OUT
TEST........................................................... 8-3
[8] Procedure H: MOTOR WINDING TEST..... 8-3
[9] Procedure I: NOISE FILTER TEST............. 8-4
[10] Procedure J: BLOWN FUSE (F1) 20A ........ 8-4
[11] Procedure K: BLOWN FUSE (F2) 8A
(NOISE FILTER) ......................................... 8-4
[12] Procedure L: GRILL HEATING ELE-
MENTS (TOP) AND CONVECTION
HEATING ELEMENT TEST ........................ 8-4
[13] Procedure M: CONTROL PANEL AS-
SEMBLY TEST ........................................... 8-4
[14] Procedure N: JOG AND SWITCH UNIT
TEST........................................................... 8-5
[15] Procedure O: RELAY TEST........................ 8-6
[16] Procedure P: PROCEDURES TO BE
TAKEN WHEN THE FOIL PATTERN ON
THE PRINTED WIRING BOARD (PWB)
IS OPEN ..................................................... 8-6
CHAPTER 9. TOUCH CONTROL PANEL ASSEM­BLY
[1] OUTLINE OF TOUCH CONTROL PAN-
EL ............................................................... 9-1
[2] SERVICING FOR TOUCH CONTROL
PANEL ........................................................ 9-1
CHAPTER 10. PRECAUTIONS FOR USING LEAD­FREE SOLDER
CHAPTER 11. COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
[1] BEFORE OPERATING ..............................11-1
[2] OUTER CASE REMOVAL .........................11-1
[3] HIGH VOLTAGE COMPONENTS RE-
MOVAL.......................................................11-1
[4] HIGH VOLTAGE TRANSFORMER RE-
MOVAL.......................................................11-2
[5] MAGNETRON REMOVAL .........................11-2
[6] CONTROL PANEL ASSEMBLY RE-
MOVAL.......................................................11-2
[7] FAN MOTOR REREPLACEMENT.............11-2
[8] TURNTABLE MOTOR REPLACEMENT....11-3
[9] CONVECTION MOTOR AND CONVEC-
TION HEATING ELEMENT REMOVAL .....11-3
[10] POSITIVE LOCK........................................11-4
[11] OVEN LAMP SOCKET REMOVAL............11-4
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CHAPTER 1. BEFORE SERVICING
[1] GENERAL IMPORTANT INFORMATION
This Manual has been prepared to provide Sharp Corp. 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.
[2] 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.
Removal of the outer wrap gives access to potentials above 250V.
All the parts marked “*” on parts list may cause undue microwave exposure, by themselves, or when they are damaged, loosened or removed.
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
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[3] CAUTION MICROWAVE RADIATION
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 absorbing load attached. Never look into an open waveguide or antenna while the device is energized.
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CHAPTER 2. WARNING TO SERVICE PERSONNEL
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
GB Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following
parts will result in electrocution. High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier assembly, High voltage harness.
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.
NL
Magnetronovens bevatten circuits die een zeer hoge spanning en stroom kunnen voortbrengen. Contact met de volgende onderdelen kan elektrocutie tot gevolg hebben. Hoogspanningscondensator, hoogspanningstransformator, magnetron, hoogspanningsgelijkrichter, hoogspannings kabelboom.
VERGEET DE VOLGENDE 3 STAPPEN NIET
1) Haal de stekker uit het stopcontact.
2) Open de deur en zorg ervoor dat hij niet dicht kan vallen.
3) Ontlaad de hoogspanningscondensator.
PAS OP VOOR DE ELECTRISCHE LADING VAN DE HOOGSPANNINGSCONDENSATOR
VERGEET DE VOLGENDE 4 STAPPEN NIET
1) Sluit de draden weer aan diezijn losgehaald voor de test.
2) Plaats de buitenmantel weer om het toestel heen (kabinet).
3) Stop de stekker weer in het stopcontact.
4) Zet de oven aan. Controleer alle functies.
Wanneer alle reparaties zijn uitgevoerd en de oven weer in elkaar is gezet, moet de het magnetronvermogen worden gecontroleerd en moet worden gecontroleerd of er geen microgolflekkage is.
The high-voltage capacitor remains charged about 60 econds after the oven has been switched off. Wait for 60 seconds and then short-circuit the connection ofthe high-voltage capacitor (that is, of the connectin­glead of the high-voltage rectifier) against the chas­siswith the use of an insulated screwdriver.
Sharp recommend that wherever possible fault-findingis carried out with the supply disconnected. It may in,some cases, be necessary to connect the supply after the out­er case has been removed, in this event carry out 3D checks and then disconnect the leads to the primary of the high voltage transformer. Ensure that these leadsre­main isolated from other components and the oven chas­sis. (Use insulation tape if necessary.) When the testing is completed carry out 3D checks and reconnectthe leads to the primary of the high voltage transformer.
Microwave ovens should not be run empty. 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 power to HIGH and set the microwave 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 re­examine the connections to the component being tested.
When all service work is completed, and the oven is fully assembled, the microwave power output should be checked and a microwave leakage test should be carriedout.
De hoogspanningscondensator blijft nog ongeveer 60 seconden lang opgeladen, nadat de oven is uitgeschakeld. Wacht 60 seconden voordat u de verbinding van de hoogspannings-condensator (m.a.w. de verbindingsdraad van de hoogspanningsgelijkrichter) met een ge soleerde schroevedraaier kortsluit tegen het chassis.
Sharp beveelt ten sterkste aan dat, voor zover mogelijk, defecten worden opgespoord wanneer de stekker uit het stopcontact is gehaald. Soms is het nodig om de stroomtoevoer weer tot stand te brengen nadat de buitenmantel verwijderd is. Herhaal dan de bovengenoemde 3 stappen en haal deelectrische draden uit de primaire zijde van de vermogenstransformator. Zorg ervoor dat deze draden ge•soleerd blijven van andere elementen en van het chassis van de oven. (Gebruik zo nodig isolatieband.) Wanneer de test is uitgevoerd, herhaalt u de bovenstaande 3 stappen en verbindt u de electrische draden weer aan de primaire zijde van de vermogenstransformator.
Magnetronovens mogen niet leeg aangezet worden. Om te controleren of er microgolf-energie binnen de oven wordt geproduceerd, plaatst u een mok met koud water op de draaitafel van de oven, sluit de deur, zet de oven op HIGH en stelt de klok van de magnetron in op twee (2) minuten. Wanneer de twee minuten voorbij zijn (klok staat op nul), controleert u voorzichtig of het water heet is. Indien het water nog steeds koud is, herhaalt u de allereerste drie stappen en controleer nogmaals de aansluitingen naar de geteste onderdelen.
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CHAPTER 3. PRODUCT SPECIFICATIONS
TEM DESCRIPTION
Power Requirements
230 Volts 50 Hertz Single phase, 3 wire earthed
Power Consumption Microwave cooking 1.5 kW Approx 6.7A
Convection cooking 2.8 kW Approx 12.2A Grill cooking 2.8 kW Approx 12.2A Dual cooking Micro and Grill ----------------2.80kW Approx 12.4A
Micro and Convection ----- 2.95kW Approx. 13.0A
Power Output
900 watts nominal of RF microwave energy (IEC60705 Test Procedure)
Operating frequency 2450 MHz Grill heating element Power Output
1300W (650W x 2)
Convection heating element Power Output
1450W
Outer Case Dimensions
Width 550 mm
Height 368 mm including foot
Depth 537 mm NOTE: The Depth does not include the door opening handle.
Cooking Cavity Dimensions
Width 375 mm NOTE: Internal capacity is calculated by measuring maximum width, depth and height.
Height 272 mm Actual capacity for holding food is less.
Depth 395 mm Turntable diameter 362 mm
Control Complement
Touch Control System
Timer (0 - 90 minutes)
Clock (1:00 - 12:59) or (0:00 - 23:59)
Microwave Power for Variable Cooking
Repetition Rate;
900W ....................................... Full power throughout the cooking time
630W ...................................... approx. 70% of FULL Power
450W ..................................... approx. 50% of FULL Power
270W ......................................approx. 30% of FULL Power
90W .......................................approx. 10% of FULL Power
Convection temperature control range:
250°C, 230°C, 220°C, 200°C, 190°C, 180°C, 160°C, 130°C, 100°C and 40°C
LESS( )/ MORE( ) buttons
LANGUAGE button
INFORMATION button
EXPRESS COOK button
EXPRESS DEFROST button
AUTO REHEAT button
AUTO COOK button
COOKING MODE dial
CONVECTION button
MICROWAVE POWER LEVEL button
TIMER/WEIGHT dial
CLOCK setting button
STOP button,
(START)/+ 1min button
Net Weight Approx. 23 kg
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CHAPTER 4. APPEARANCE VIEW
[1] OVEN
1. Grill heating element
2. Oven lamp
3. Control panel
4. Shelf runners
5. Waveguide cover
6. Oven cavity
7. Coupling
8. Door seals and sealing surfaces
9. Door opening handle
10.Air-vent openings
11.Outer cabinet
12.Power cord
13.Turntable
14.Turntable support 15.High Rack 16.Low Rack 17.Baking tin 18. Square shelf 19. Square fin
[2] TOUCH CONTROL PANEL
Digital display and indicators:
1. COOKING IN PROCESS indicator
2. GRIL indicator
3. CONVECTION indicator
4. MICROWAVE indicator
5. INFO indicator
Operating buttons:
6. INFORMATION button
7. LANGUAGE button
8. EXPRESS DEFROST button
9. AUTO REHEAT button
10.COOKING MODE dial: Rotate the dial so that indicator points to appropriate symbol.
for microwave cooking
for microwave cooking with GRILL
for microwave cooking with CONVECTION
for GRILL
for CONVECTION
11. CONVECTION button
Press to change the convection temperature.
12. TIMER/WEIGHT knob
Rotate the knob to enter either the cooking/defrosting time or weight food.
13. (START) / 1 min button (See note)
NOTE: This features is disabled after three minutes when the oven is not in use. This feature is
automatically enabled when the door is opened and closed or the STOP button is pressed.
14. STOP button
15. CLOCK SETTING button
16. MICROWAVE POWER LEVEL button: Press to change the microwave power setting.
17. AUTO COOK button
18. EXPRESS COOK button 19. LESS / MORE buttons
15
3
214
12
11
10
13
8
9
14
16
18
(R-939(BK) only)
19
(R-939(BK) only)
7 6 5
17
3
4 5
6
7
9
8
10
12
13
14
16
17
15
11
18
1
2
19
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CHAPTER 5. OPERATION SEQUENCE
[1] OFF CONDITION
Closing the door activates the monitored latch switch and the stop switch.
IMPORTANT
When the oven door is closed, the contacts COM-NC of the moni­tor switch must be open. When the microwave oven is plugged in a wall outlet (230V / 50Hz), the line voltage is supplied to the noise filter.
Figure O-1 on page 14-1
1. The control unit is not energized. The display shows nothing (Fig. O-1 (a)).
2. Open the door. The contacts (COM-NC) of the monitored latch switch are closed and the control unit is energized. Then contacts of relays RY1
and RY5 are closed, and the oven lamp will light and the display will show “SELECT LANGUAGE” in 5 languages. (Fig. O-1(b)).
NOTE: NOTE: Once the language is selected using the LANGUAGE
key, the display will show “ENERGY SAVE MODE TO GO OUT OF ENERGY SAVE MODE SET CLOCK” when the oven is plugged in.
3. Close the door. The contacts (COM-NC) of the monitored latch switch are opened and the contacts of relay RY1
are opened and the oven lamp will be turned off. The display will show “ . 0". (Fig. O-1(c)).
NOTE: Energy save mode
1) If the oven has not been used for more than 3 minutes, the contacts of the relay RY5
will be opened and the control unit will be not energized. Open and close the door, the control unit will resume.
2) If the clock is set, this energy save mode does not work.
3) If the display shows different messages from ENERGY SAVE MODE, the oven may be set in demo mode. Close the door, see operation manual to cancel demo mode.
[2] MICROWAVE COOKING CONDITION
1. HIGH COOKING
Rotate the COOKING MODE dial to the micro setting. And press the POWER LEVEL button once. And enter the cooking time by rotating the TIMER/WEIGHT dial. And start the oven by pressing START but­ton.
Function sequence
Figure O-2 on page 14-2
1. The line voltage is supplied to the primary winding of the high volt­age 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 secondary winding.
2. The filament winding voltage (3.3 volts) heats the magnetron fila­ment and the high voltage (2000 volts) is sent to the voltage dou­bling circuit, where it is doubled to negative voltage of approximately 4000 volts D.C..
3. The 2450 MHz microwave energy produced in the magnetron gen­erates a wavelength of 12.24 cm. This energy is channelled through the waveguide (transport channel) into the oven cavity, where the food is placed to be cooked.
4. When the cooking time is up, a signal tone is heard and the relays RY1 + RY2 + RY6
go back to their home position.
The circuits to the oven lamp, high voltage transformer, fan motor and turntable motor are cut off.
5. When the oven door is opened during a cooking cycle, the switches come to the following condition.
The circuit to the high voltage transformer is cut off when the contacts of relay RY2
, and the contacts (COM-NO) of the monitored latch
switch SW1 and monitor switch SW3
are made open. The circuit to the
fan motor is cut off when the relay RY6
is made open. The circuit to the turntable motor is cut off when the contacts (COM-NO) of the moni­tored latch switch SW1
are made open. The oven lamp remains on even if the oven door is opened after the cooking cycle has been inter­rupted, because the relay RY1
stays closed. Shown in the display is
remaining time.
6. MONITOR SWITCH CIRCUIT
The monitor switch SW3
is mechanically controlled by the oven door, and monitors the operation of the monitored latch switch SW1.
1) When the oven door is opened during or after the cycle of a
cooking program, the monitored latch switch SW1 and stop switch SW2
must open their contacts (COM-NO) first. And the
contacts (COMNC) of the monitored latch switch SW1
are made closed. After that the contacts (COM-NC) of the monitor switch SW3 can be closed and the contacts (COM-NO) of monitor switch SW3
are made open.
2) When the oven door is closed, the contacts (COMNC) of the monitor switch SW3
must be opened and the contacts (COM-
NO) of monitor switch SW3
must be closed. After that the con-
tacts (COM-NO) of the monitored latch switch SW1
and the stop
switch SW2
are made closed. And the contacts (COM-NC) of
the monitored latch switch SW1 are made open.
3) When the oven door is opened and the contacts (COM-NO) of the monitored latch switch SW1
remain closed, the fuse F2 F8A
will blow. Because the relay RY1
and monitor switch SW3 are
closed and a short circuit is caused.
2. MEDIUM HIGH, MEDIUM, MEDIUM LOW, LOW COOKING
When the microwave oven is preset for variable cooking power, the line voltage 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 RY2
. The following levels of micro-
wave power are given.
CONNECTED COMPONENTS RELAY Oven lamp, Turntable motor RY1 High voltage transformer RY2 Fan motor, RY6
CONDITION
SWITCH CONTACT
DURING
COOKING
DOOR OPEN
(NO COOKING) Monitored latch switch
COM-NO COM-NC
Closed
Opened
Opened
Closed
Stop switch COM-NO Closed Opened
Monitor switch
COM-NO COM-NC
Closed
Opened
Opened
Closed
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SETTING;
NOTE: The ON/OFF time ratio does not exactly correspond to the
percentage of microwave power, because approx. 3 seconds are needed for heating up the magnetron filament.
[3] GRILL COOKING CONDITION
1. TOP GRILL (Figure O-3)
In this condition the food is cooked by the top grill heating element . Rotate the COOKING MODE dial to GRILL setting. And enter the desired cooking time by rotating the TIMER/WEIGHT dial. When the START button is pressed, the following operations occur:
1. The numbers on the digital readout start the count down to zero.
2. The oven lamp, cooling fan motor and turntable motor are ener­gized.
3. The relay RY3 is energized and the main supply voltage is applied to the top grill heating elements.
4. Now, the food is cooked by the top grill heating elements.
NOTE: The convection cooking condition will be carried out simulta-
neously until the temperature of the oven cavity rise to 220°C.
[4] CONVECTION COOKING CONDITION
1. PRE-HEATING (by 40°C - 130°C)
Rotate the COOKING MODE dial to the convection setting. And programme the desired convection temperature of 40°C - 130°C by touching CONVECTION button. When the START button is touched, the following operations occur:
1. The relays RY1, RY6
and RY7 are energized, the oven lamp, turn-
table motor, fan motor and convection motor are turned on.
2. The relay RY4
is energized and the main supply voltage is applied
to the convection heating element.
3. After the temperature of oven cavity rises to the selected one, the oven will continue to turned the convection heating element on and off to maintain the temperature for 30 minutes.:
2. PRE-HEATING (by 160°C - 250°C)
Rotate the COOKING MODE dial to the convection setting. And programme the desired convection temperature of 160°C - 250°C by touching CONVECTION button. When the START button is touched, the following operations occur:
1. The relays RY1, RY6
and RY7 are energized, the oven lamp, turn-
table motor, fan motor and convection motor are turned on.
2. The relay RY4
and RY3 are is energized and the main supply volt­age is applied to the convection heating element and the grill heat­ing elements.
3. After the temperature of oven cavity rises to the selected one, the oven will continue to turned the convection heating element on and off to maintain the temperature for 30 minutes. And simultaneously the grill heating element will be operated at 10% power output.
3. CONVECTION COOKING (by 250°C)
Rotate the COOKING MODE dial to the convection setting. And enter the cooking time by rotating the TIMER/ WEIGHT dial. And select the desired cooking temperature 250°C by pressing the CON­VECTION button. When the START button is pressed, the following operations occur:
1. The relays RY1, RY6
and RY7 are energized, the oven lamp, turn-
table motor, fan motor and convection motor are turned on.
2. The relay RY4
and RY3 are energized and the main supply voltage is applied to the convection heating element and the grill heating elements.
3. The oven will continue to turn the convection heating element on and off to maintain the temperature for the programmed cooking time. And simultaneously the grill heating elements will be operated at 10% power output.
4. CONVECTION COOKING (by 40°C - 230°C)
Rotate the COOKING MODE dial to the convection setting. And enter the cooking time by rotating the TIMER/ WEIGHT dial. And select the desired cooking temperature 40°C - 230°C by pressing the CONVECTION button. When the START button is pressed, the follow­ing operations occur:
1. The relays RY1, RY6
and RY7 are energized, the oven lamp, turn-
table motor, fan motor and convection motor are turned on.
2. The relay RY4
is energized and the main supply voltage is applied
to the convection heating element.
3. The oven will continue to turn the convection heating element on and off to maintain the temperature for the programmed cooking time.
[5] DUAL COOKING CONDITION
1. MICROWAVE AND CONVECTION (Figure O-5a)
Rotate the COOKING MODE dial to DUAL 1 setting. And enter the desired cooking time by rotating the TIMER/WEIGHT dial. And press POWER LEVEL button to set the desired microwave power. And press the CONVECTION button to set the cooking temperature. When the START button is pressed, the following operations occur:
NOTE: The 100% microwave power level can not be selected.
When the START button is touched, the following operations occur:
1. The numbers on the digital read-out start the count down to zero.
2. The oven lamp, fan motor, turntable motor and convection motor are energized.
3. The relay RY4
will be energized and the main supply voltage is
applied to the convection heating element.
4. The relay RY2
is energized and the microwave energy is generated
by magnetron.
5. Now, the food is cooked by microwave and convection energy simultaneously.
2. MICROWAVE AND TOP GRILL (Figure O-5b)
Rotate the COOKING MODE dial to DUAL 2 setting. And enter the desired cooking time by rotating the TIMER/ WEIGHT dial. And press POWER LEVEL button to set the desired microwave power. When the START button is pressed, the following operations occur:
1. The numbers on the digital read-out start the count down to zero.
2. The oven lamp, fan motor and turntable motor are energized.
3. The relay RY3
is energized and the main supply voltage is applied
to the grill heating elements.
4. The relay RY2
is energized and the microwave energy is generated
by magnetron.
5. Now, the food is cooked by microwave and grill simultaneously.
100% (HIGH)
32 sec. ON
70%
(MEDIUM
HIGH)
Approx. 70%
100%
24 sec. ON 8 sec. OFF
14 sec. OFF
20 sec. OFF
26 sec. OFF
50% (MEDIUM) Approx. 50%
18 sec. ON
30%
(MEDIUM
LOW)
Approx. 30%
12 sec. ON
10% (LOW) Approx. 10%
6 sec. ON
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5 – 3
[6] ON/OFF TIME RATIO
In dual cooking, the magnetron operate within a 48 second time base. The following table is the ON / OFF time ratio at each power output of the magnetron.
[7] AUTOMATIC COOKING
Auto Cook functions automatically work out the correct cooking mode and cooking time and/or cooking temperature. They will cook accord­ing to the special cooking sequence.
[8] POWER OUTPUT REDUCTION
After the same cooking mode is carried out for more than the basis cooking time, the power output is automatically reduced by turning the control relays on and off intermittently, as shown in the table below. This is to protect the oven door against temperature rising.
NOTE: 1) If the multiple sequence cooking is carried out in the same
mode, the basis cooking time is calculated from the first.
2) Even if the cooking is stopped by the STOP key or opening the door, the basis cooking time is calculated from the first.
3) If the same cooking mode is repeated within 1 minute and 15 seconds, the basis cooking time is calculated from the first.
4) If the same menu of Automatic Cooking is repeated within 1 minute and 15 seconds, the power output of the micro­wave or the grill will be reduced to 70% after 20 minutes when the oven is started at first.
[9] FAN MOTOR OPERATION
(in Grill, Convection and Dual mode)
When oven is stopped during cooking, or after the cooking is com­pleted, the fan motor will operate if the oven cavity temperature is above 120°C, and the fan motor will stop if the oven cavity tempera­ture is below 105°C.
[10] CONVECTION MOTOR OPERATION
If the temperature of oven cavity is higher than 120°C after and when operated by 250°C convection cooking, 250°C dual convection cook­ing or 250°C preheating, the convection motor will operate for maxi­mum 1 minute until the oven cavity temperature drops below 105°C.
ON/OFF TIME RATIO
In grill cooking, convection cooking or dual cooking, the top heater, bottom heater or magnetron operate within a 48 second time base. The following table is the ON / OFF time ratio at each power output of the top heaters, bottom heater or magnetron.
POWER OUTPUT ON TIME OFF TIME
100% 48 sec. 0 sec.
70% 36 sec. 12 sec. 50% 26 sec. 22 sec. 30% 16 sec. 32 sec. 10% 8 sec. 40 sec.
Cooking mode
Basis cooking time (minutes)
Reduced power
output (%)
Time base
(seconds) Microwave (100%) 20 70 32 Grill 15 70 48 Convection No reduction
D U
A L
Micro. (70%) + Grill
40 (Micro.) 50 48 15 (Grill) 50 48
Micro. (100%) + Grill
15 (Micro.) 50 48 15 (Grill) 50 48
Micro. (70%) + Conv.
40 (Micro.) 50 48
No reduction
Page 13
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6 – 1
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Service Manual
CHAPTER 6. FUNCTION OF IMPORTANT COMPONENTS
[1] DOOR OPEN MECHANISM
The door can be opened by pulling the door handle.
When the door handle is pulled, the latch head is moved upward, and released from the latch hook now the door can be opened.
Figure D-1. Door Open Mechanism
[2] MONITORED LATCH SWITCH (SW1)
1. When the oven door is closed, the contacts (COM-NO) of the switch must be closed. And the contacts (COMNC) must be opened.
2. When the oven door is opened, the contacts (COMNO) of the switch must be opened. And the contacts (COM-NC) must be closed.
[3] STOP SWITCH (SW2)
1. When the oven door is closed, the contacts (COM-NO) of the switch must be closed.
2. When the oven door is opened, the contacts (COMNO) of switch must be opened.
[4] MONITOR SWITCH (SW3)
The monitor switch is activated (the contacts opened) by the upper latch head on the door while the door is closed. The switch is intended to render the oven inoperative by means of blowing the fuse F2
F8A
when the contacts of the monitored latch switch SW1
fail to open when
the door is opened.
Function
1. When the door is opened, the contacts (COM-NC) of monitor switch SW3
close (to the ON condition) due to their being normally closed and contacts (COM-NO) open. At this time the contacts (COM-NO) of monitored latch switch SW1
is in the OFF condition
(contacts open) due to their being normally open contact switches.
2. As the door goes to a closed position, the monitor switch SW3
con­tacts (COM-NC) are opened and contacts (COM-NO) closed and then contacts (COM-NO) of monitored latch switch SW1
and stop
switch SW2
are closed.(On opening the door, each of these
switches operate inversely.)
3. If the door is opened and the monitored latch switch SW1
contacts
(COM-NO) fail to open, the fuse F2
F8A blows immediately after
closing of the monitor switch SW3
(COM-NC) contacts.
CAUTION: BEFORE REPLACING A NOISE FILTER (BLOWN FUSE
F2
F8A), TEST THE MONITORED LATCH SWITCH SW1 AND MONITOR SWITCH SW3 FOR PROPER OPERA­TION. (REFER TO CHAPTER “TEST PROCEDURE”).
[5] FUSE (F1) 20A 250V
If the wire harness or electrical components are shortcircuited, this fuse F1
20A blows to prevent an electric shock of fire hazard.
[6] FUSE (F2) F8A 250V (NOISE FILTER)
1. If the wire harness or electrical components are shortcircuited, this fuse blows to prevent an electric shock or fire hazard.
2. The fuse also blows when the monitored latch switch SW1
remains closed with the oven door open and when the monitor switch SW3 contact (COM-NC) closes.
3. The fuse also blows when the asymmetric rectifier, H.V. rectifier,. H.V. wire harness, H.V. capacitor, magnetron or secondary winding of high voltage transformer is shorted.
[7] TC TRANSFORMER
T/C transformer converts A.C. line voltage into low voltage to drive the control unit.
[8] THERMAL CUT-OUT (TC1) 125C (MG)
This thermal cut-out protects the magnetron against overheat. If the temperature goes up higher than 125°C because the fan motor is interrupted or the ventilation openings are blocked, the thermal cut-out TC1
will open and switch off all the electrical parts. The defective ther-
mal cut-out must be replaced with a new one.
[9] THERMAL CUT-OUT (TC2) 170C (GRILL)
This thermal cut-out protects the oven against the overheat during grill cooking, convection cooking or dual cooking. If the temperature rises above 170°C because the fan motor is interrupted, the air inlet duct is blocked or the ventilation openings are obstructed, the thermal cut-out TC2
opens and switches off all the electrical parts. When the cut-out cools itself down to the operating temperature of 155°C, the contacts of the thermal cut-out will close again.
[10] THERMAL CUT-OUT (TC3) 170C (CONV.)
This thermal cut-out protects the convection motor against overheat­ing. If the temperature of the thermal cut-out TC3
rises above 170°C because the convection fan is interrupted, the ventilation openings are obstructed or the other abnormal matter occurs, the thermal cut-out opens and switches off the convection heating element and the other electrical parts. When the cut-out cools itself down to the operating temperature of 155°C, the contacts of the thermal cut-out will close again.
[11] ASYMMETRIC RECTIFIER
The asymmetric rectifier is solid state device that prevents current flow in both directions. And it prevents the temperature rise of the high volt­age transformer by blowing the fuse F2
F8A when the high voltage
rectifier is shorted.
Latch hook
Door
SW2: Stop switch
Latch Heads
SW3: Monitor switch
SW1: Monitored
latch switch
Tab
D2 D1
ASYMMETRIC RECTIFIER
HIGH VOLTAGE RECTIFIER
Page 14
R939(W)
6 – 2
the asymmetric rectifier is 1.7 KV. D1 and D2 of the asymmetric recti­fier or high voltage rectifier are shorted when the each peak reverse voltage goes beyond the each rated peak reverse voltage. (The pro­cess of the blowing the fuse F2
F8A.)
1. The high voltage rectifier is shorted by some fault when microwave cooking or dual cooking.
2. The peak reverse voltage of D2 of the rectifier goes beyond the rated peak reverse voltage 1.7 KV in the voltage doubler circuit.
3. D2 of the rectifier is shorted.
4. The large electric currents flow through the high voltage winding of the high voltage transformer.
5. The large electric currents beyond 8A flow through the primary winding of the high voltage transformer.
6. The fuse F2
F8A blows by the large electric currents.
7. The power supplying to the high voltage transformer is cut off.
[12] NOISE FILTER
The noise filter assembly prevents radio frequency interference that might flow back in the power circuit.
[13] TURNTABLE MOTOR (TTM)
The turntable motor rotates the turntable.
[14] FAN MOTOR (FM)
The fan motor drives a blade which draws external cool air. This cool air is directed through the air vanes surrounding the magnetron and cools the magnetron. This air is channelled through the oven cavity to remove steam and vapours given off from heating food. It is then exhausted through the exhausting air vents of the oven cavity.
[15] CONVECTION MOTOR (CM)
The convection motor drives the convection fan and provide the heated air.
[16] GRILL HEATING ELEMENT (GH)
The grill heating elements are provided to brown the food and are located on the top of the oven cavity.
[17] CONVECTION HEATING ELEMENT (CH)
The convection heating element situated at the rear of the oven cavity. It is intended to heat air driven by the convection fan. The heated air is kept in the oven and force-circulated and reheated by the convection heating element.
[18] CONVECTION COOKING SYSTEM
This oven is designed with a hot air heating system where food is heated by forced circulation of the hot air produced by the grill heaters. The air heated by the grill heating elements is circulated through the convection passage provided on the outer casing of the oven cavity by means of the convection fan which is driven by the convection motor. It is then enters the inside of the oven through the vent holes provided on the back side of the oven. Next, the hot air heats the food on the turntable and leaves the oven cavity through the vent in the oven cav­ity rear wall. In this way, the hot air circulates inside the oven cavity to raise its temperature and, at the same time, comes into contact with the food being cooked. When the temperature inside the oven cavity reaches the selected temperature, the heating elements are de-ener­gized. When the temperature inside the oven cavity drops below the selected temperature, the heating elements are energized again. In this way, the inside of the oven cavity is maintained at approximately the selected temperature.
When the convection time reaches “0”, the heating elements are deen­ergized and the convection fan stops operating and the oven shuts off. At that time if the cavity air temperature has risen above 120°C, the fan motor remains rotating. Automatically the fan motor will be shut down at low temperature (less than 105°C).
Figure D-2. Convection Cooking System
[19] FIRE SENSING FEATURE
The oven will stop its operation when there is a fire in the oven cavity in microwave cooking condition. LSI measures the voltage across the temperature measurement circuit intermittently within 32-seconds time base since the oven is started in microwave cooking condition. The oven will stop its operation when the difference of the voltage is more than 0.39 volts in microwave cooking condition.
1. Within a 32-seconds base, the thermistor is energized for 2 sec­onds. At that time, the voltage across the temperature measure­ment circuit is measured.
2. The oven carries out the procedure above again. If the second volt­age is 0.39V higher than first voltage, LSI judges it is a fire in the oven cavity and stop the oven.
3. When LSI judges it is a fire in the oven cavity, LSI will switch off the relays to high voltage transformer and fan motor and LSI stops counting down.
[20] OPEN JUDGE BY THERMISTOR
1. If the temperature of the thermistor does not rise to more than 40°C after 4 minutes and 15 seconds from when the oven is started in convection, grill or dual cooking mode, the oven is turned off.
2. When the thermistor or the wire harness to the thermistor is opened, the oven is turned off after 4 minutes and 15 seconds because this condition is same as above.
[21] DAMPER OPEN-CLOSE MECHANISM
Damper position is set automatically by damper motor DM, damper switch and motor cam. These components are operated by a signal that judges if microwave cooking or convection cooking operation is selected by the CPU unit.
Door
Oven Cavity
Grill Heating Elements
Convection Passage
Cooling Fan
Convection Motor
Convection Fan
Turntable
Turntable Motor
Roller Stay
Convection Heating Element
THERMISTOR
Sensing
Voltage
ON
OFF
ON
OFF
Sensing the voltage across temperature measurement circuit.
Page 15
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6 – 3
1. Microwave Cooking:
Damper is in the open position, because a portion of cooling air is channelled through the cavity to remove steam and vapours given off from the heating foods. It is then exhausted at the top of the oven cav­ity into a condensation compartment.
2. Convection Cooking:
Damper is in the closed position, so that no hot air will be allowed to leak out the oven cavity.
3. Damper Operation
1. When power supply cord is plugged in or when the control unit resumes after energy save mode finishes:
1) When power supply cord is plugged in, a signal is sensed in the
control unit, and operates shut-off relay (RY8).
2) Contacts of shut-off relay (RY8) close, the damper motor DM
is
energized, opening the damper door.
3) When the damper is moved to the open position by the damper
cam, damper switch SW4 is closed (ON position).
4) The signal of damper switch SW4 is re-sensed in the control
unit and shut-off relay (RY8) is turned off.
5) The rated voltage to the damper motor DM
is stopped and the
motor turns off.
2. When oven is microwave cooking: Damper is in the open position
3. When oven is convection cooking:
1) Damper motor DM
is energized right after the oven is started.
2) When damper is in the closed position (damper switch SW4
is OFF), its signal is sensed by the control unit, and shut-off relay (RY8) is de-energized.
3) The damper is held in the closed position during the convection cooking operation.
4) At the end of the convection cooking, when the fan motor FM stops, shut-off relay (RY8) is energized, and the damper is returned to the open position.
NOTE: If the damper door is not in the proper position, closed during
convection, grill or dual, or open during microwave, the control unit will stop oven operation after 1 minute.
4. Operation of damper is shown below.
Cooking Mode Operation of Damper Microwave cooking Open Convection cooking Closed Grill; during backed up with convection
heating element
Closed
Grill; after convection heating element backed up has stopped
Open
Dual (Microwave and Convection) Closed Dual (Microwave and Grill) Open Open Fire sensing condition Closed Closed
Page 16
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7 – 1
R939(W)
Service Manual
CHAPTER 7. TROUBLESHOOTING GUIDE
[1] FOREWORD
When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing 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 because of a blown fuse F2 (F8A) in the monitored latch switch SW1 - monitor switch SW3 circuit, check the moni­tored latch switch SW1
and monitor switch SW3 before replacing the noise filter (fuse F2 (F8A)).
Page 17
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7 – 2
[2] CHART
Fuse F2 (F8A) blows when the door is opened.
Home fuse blows when power cord is plugged into wall outlet.
Fuse F1 20A blows when power cord is plugged into wall outlet.
Nothing appears in display when power cord is plugged into wall outlet
and the door is opened and closed.
Display does not operate properly when STOP button is pressed.
Oven lamp does not light when door is opened. (Display operates.)
Oven does not start when the START button is pressed. (Display operates.)
Oven lamp does not light and turntable motor does not operate.
Fan motor does not operate. (Oven lamp lights.)
Convection fan motor does not operate. (Fan motor operates.)
Turntable motor does not operate. (Oven lamp lights.)
Oven or any electrical parts (except fan motor) does not stop when
cooking time is 0 or STOP button is pressed.
Oven stops after 4 minutes and 15 seconds since START button is
pressed. (Except Microwave mode and Dual cook mode)
Display operates properly but all electrical parts do not operate.
Oven goes into cook cycle but shuts down before end of cooking cycle.
After cooking, the temperature of oven cavity is higher than 120ºC but
fan motor does not operate.
The oven stops 1 minute after starting.
Oven seems to be operating but little or no heat is produced in oven
load. (Microwave power control is set at 100%)
Oven does not seem to be operating properly during variable cooking
condition except 100% cooking condition.
Oven goes into cook cycle but shuts down before end of cooking cycle.
Convection cooking mode does not heat.
Oven seems to be operating but the temperature in the oven cavity is
lower or higher than preset one.
Grill heating element does not operate.
Oven goes into cook cycle but shuts down before end of cooking cycle.
Oven seems to be operating but little or no heat is produced in oven
load. (Microwave power does not seem to be generated properly)
Oven seems to be operating but the temperature in the oven cavity is
lower or higher than preset one.
Convection heating elements do not heat.
Grill heating element does not heat.
OFF
CONDITION
COOKING
CONDITION
(COMMON MODE)
MICROWAVE
COOKING
CONDITION
GRILL COOKING
CONDITION
CONVECTION
COOKING
CONDITION
DUAL COOKING
CONDITION
(COMMON MODE)
DUAL COOKING
CONDITION
(MICRO./CONV.)
DUAL COOKING
CONDITION
(MICRO./GRILL)
CONDITION
PROBLEM
BLOCKED
COOLING FAN
BLOCKED
CONVECTION FAN NO POWER AT WALL OUTLET HOME FUSE OR BREAKER MIS-ADJUSTMENT OF SWITCHES BLOCKED VENTILATION OPENINGS OPENED WIRE HARNESS SHORTED WIRE HARNESS OVEN LAMP OR SOCKET POWER SUPPLY CORD FOIL PATTERN ON P.W.B. RELAY RY8 RELAY RY7 RELAY RY6 RELAY RY5 RELAY RY4 RELAY RY3 RELAY RY2 RELAY RY1 KEY UNIT TOUCH CONTROL PANEL TC TRANSFORMER CONVECTION HEATING ELEMENT GRILL HEATING ELEMENT NOISE FILTER (FUSE F2 F8A) FUSE F1 20A NOISE FILTER DAMPER MOTOR DM CONVECTION FAN MOTOR FAN MOTOR FM TURNTABLE MOTOR TM THERMAL CUT-OUT 170ºC TC3 THERMAL CUT-OUT 170ºC TC2 THERMAL CUT-OUT 125ºC TC1 THERMISTOR DAMPER SWITCH SW4 MONITOR SWITCH SW3 STOP SWITCH SW2 MONITORED LATCH SWITCH SW1 HIGH VOLTAGE CAPACITOR H.V. HARNESS H.V. RECTIFIER ASSEMBLY HIGH VOLTAGE TRANSFORMER MAGNETRON
TEST PROCEDURE
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
I J K L L MN OOOOOOOOP
Page 18
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Service Manual
CHAPTER 8. TEST PROCEDURES
[1] Procedure A: MAGNETRON TEST
NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL WHILE THE OVEN IS IN OPERATION.
CARRY OUT 3D
CHECKS.
Isolate the magnetron from the high voltage circuit by removing all leads connected to the filament terminal.
To test for an open circuit filament use an ohmmeter to make a continuity test between the magnetron filament terminals, the meter should show a reading of less than 1 ohm.
To test for a short circuit filament to anode condition, connect ohmmeter between one of the filament terminals and the case of the magnetron (ground). This test should be indicated an infinite resistance. If a low or zero resistance reading is obtained then the magnetron should be replaced.
MICROWAVE OUTPUT POWER (IEC60705)
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 IEC test procedure, 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(sec-
ond), approximately P x t/4.187 calorie is generated. On the other hand, if the temperature of the water with V(ml) rises T (°C) during this microwave
heating 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) Select stirring devices and measuring instruments in order to minimize addition or removal of heat.
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" is measured while the microwave generator is operating at full power. Magnetron filament heat-up time is not included.
NOTE: The operation time of the microwave oven is "t + 3" sec. 3 sec. is magnetron filament heat-up time.
Measuring method:
1) 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 100% for the temperature of the water rises by a value T of 10°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.
JUDGEMENT: The measured output power should be at least ± 15 % of the rated output power.
CAUTION: 1°C CORRESPONDS TO 90 WATTS. REPEAT MEASUREMENT IF THE POWER IS INSUFFICIENT.
The formula is as follows;
P x t / 4.187 = V x T+ 0.55 x mc (T2-T0)/4.187 P (W) = 4.187 x V x T / t + 0.55 x mc (T2-T0)/t Our condition for water load is as follows:
Room temperature (T0) ......................... around 20°C Power supply ........................... VoltageRated voltage
Water load .........................................................1000 g Initial temperature (T1) .................................... 10±1°C
Heating time ..................................................... 47 sec. Mass of container (mc) ...................................... 330 g
T2 .................................................... Final Temperature T = T2 - T1 P = 90 x T + 0.55 x mc (T2-T0)/47
Room temperature ................................................................... To = 21°C
Initial temperature ..................................................................... T1 = 11°C
Temperature after (47 + 3) = 50 sec ...................................... T2 = 21°C
Temperature difference Cold-Warm ( T = T2 - T1) .......... T = 10°C
Measured output power
The equation is "P = 90 x T" .................... P = 90 x 10°C = 900 Watts
Page 19
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8 – 2
[2] Procedure B: HIGH VOLTAGE TRANSFORMER TEST
1. CARRY OUT 3D CHECKS.
2. Disconnect the leads to the primary winding of the high voltage 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 winding. The following readings should be obtained:
a.Primary winding -------------------- approximately 1.9 Ω
b.Secondary winding --------------- approximately 123 Ω
c.Filament winding --------------------------- less than 1 Ω
If the readings obtained are not stated as above, then the high voltage transformer is probably faulty and should be replaced.
3. Also, the high voltage transformer has the thermal cut-out in the primary coil. The thermal cut-out will open when the temperature of the thermal cut-out in the primary coil reaches approximately 150°C. The thermal cut-out resets automatically at 130°C. If an ohmmeter indicates an open cir­cuit under normal condition, replace the high voltage transformer because the primary coil (thermal cut-out) has opened. An open primary coil (thermal cut-out) indicates overheating of the high voltage transformer. Check for restricted air flow to the high voltage transformer, especially the ventilation opening.
4. CARRY OUT 4R
CHECKS.
[3] Procedure C: HIGH VOLTAGE RECTIFIER TEST
CARRY OUT 3D CHECKS.
Isolate the high voltage rectifier assembly from the HV circuit. The high voltage rectifier can be tested 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. The normal resistance is infinite in one direction and more than 100 kΩ in the other direction.
CARRY OUT 4R
CHECKS.
ASYMMETRIC RECTIFIER TEST
CARRY OUT 3D
CHECKS.
Isolate the high voltage rectifier assembly from the HV circuit. The asymmetric rectifier can be tested using an ohmmeter set to its highest range across the terminals A+B of the asymmetric rectifier and note the reading obtained. Reverse the meter leads and note this second reading. If an open circuit is indicated in both directions then the asymmetric rectifier is good. If the asymmetric rectifier is shorted in either direction, then the asymmetric rectifier is faulty and must be replaced with high voltage rectifier. When the asymmetric rectifier is defective, check whether magnetron, high voltage rectifier, high voltage wire or filament winding of the high voltage transformer is shorted.
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, BECAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE SHOWN IN BOTH DIRECTIONS.
[4] Procedure D: HIGH VOLTAGE CAPACITOR TEST
CARRY OUT 3D CHECKS.
1. Isolate the high voltage capacitor from the circuit.
2. Continuity check must be carried out with measuring instrument which is set to the highest resistance range.
3. A normal capacitor shows continuity for a short time (kick) and then a resistance of about 10MΩ after it has been charged.
4. A short-circuited capacitor shows continuity all the time.
5. An open capacitor constantly shows a resistance about 10 MΩ because of its internal 10MΩ resistance.
6. When the internal wire is opened in the high voltage capacitor shows an infinite resistance.
7. The resistance across all the terminals and the chassis must be infinite when the capacitor is normal.
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.
1000g
1000g
1000g
T1 C
T2 C
Heat up for 50 sec.
D2 D1
ASYMMETRIC RECTIFIER
HIGH VOLTAGE RECTIFIER
AB
C
Page 20
R939(W)
8 – 3
If incorrect reading are obtained, the high voltage capacitor must be replaced.
CARRY OUT 4R
CHECKS.
[5] Procedure E: SWITCH TEST
CARRY OUT 3D CHECKS.
Isolate the switch to be tested and using an ohmmeter check between the terminals as described in the following table.
If incorrect readings are obtained, make the necessary switch adjustment or replace the switch.
CARRY OUT 4R
CHECKS.
[6] Procedure F: THERMISTOR TEST
CARRY OUT 3D CHECKS.
Disconnect the connector B from CPU unit. Measure the resistance of the thermistor with an ohmmeter. Connect the ohmmeter leads to Pin No's C1 and C3 of the thermistor harness.
If the meter does not indicate above resistance, replace the thermistor.
CARRY OUT 4R
CHECKS.
[7] Procedure G: 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.
If incorrect readings are obtained, replace the thermal cut-out.
An open circuit thermal cut-out (MG) TC1
indicates that the magnetron has overheated, this may be due to resistricted ventilation, cooling fan failure.
An open circuit thermal cut-out (GRILL) TC2
indicates that the oven cavity has overheated, this may be due to no load operation.
An open circuit thermal cut-out (CONV.) TC3
indicates that the convection fan winding has overheated, this may be due to resistricted ventilation or
locked cooling fan or locked convection fan motor.
CARRY OUT 4R
CHECKS.
[8] Procedure H: MOTOR 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.
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R
CHECKS.
Table: Terminal Connection of Switch Plunger Operation Common terminal to Normally open terminal Common terminal to Normally close terminal Released Open circuit Short circuit Depressed Short circuit Open circuit.
Room Temperature Resistance
20°C - 30°C Approximately 359.9 kΩ - 152 kΩ
Table: Thermal Cut-out Test
Parts Name
Temperature of “ON” condition
(closed circuit).
Temperature of “OFF” condition
(open circuit).
Indication of ohmmeter (When room temperature is approx. 20°C.)
Thermal cut-out TC1
125°C This is not resetable type. Above 125°C Closed circuit
Thermal cut-out TC2
170°C Cuts back in at 155°C. Above 170°C Closed circuit
Thermal cut-out TC3
170°C Cuts back in at 155°C. Above 170°C Closed circuit
Table: Resistance of Motor
Motors Resistance Fan motor Approximately 398.9 Ω Turntable motor Approximately 14.7 kΩ Convection fan motor Approximately 183.7 kΩ Dumper motor Approximately 14.7 kΩ
Page 21
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[9] Procedure I: NOISE FILTER TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of the noise filter. Using an ohmmeter, check between the terminals as described in the following table.
If incorrect readings are obtained, replace the noise filter unit.
CARRY OUT 4R
CHECKS.
[10] Procedure J: BLOWN FUSE (F1) 20A
CARRY OUT 3D CHECKS.
If the fuse F1
20A 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.
[11] Procedure K: BLOWN FUSE (F2) 8A (NOISE FILTER)
CARRY OUT 3D CHECKS.
1. If the fuse F2
F8A is blown when the door is opened, check the monitored latch switch SW1 and monitor switch SW3.
2. If the fuse F2
F8A is blown by incorrect door switching replace the defective switch(es) and the noise filter.
3. If the fuse F2
F8A is blown, there could be shorts in the asymmetric rectifier or there is a ground in wire harness. A short in the asymmetric rectifier may be occurred due to short or ground in H.V. rectifier, magnetron, high voltage transformer or H.V. wire. Check them and replace the defective parts or repair the wire harness.
CARRY OUT 4R
CHECKS.
CAUTION: REPLACE NOISE FILTER.
[12] Procedure L: GRILL HEATING ELEMENTS (TOP) AND CONVECTION HEATING ELE­MENT TEST
CARRY OUT 3D CHECKS.
Before carrying out the following tests make sure the heating element is cool completely.
1. Resistance of heater.
Disconnect the wire leads to the heating element to be tested. Using ohmmeter with low resistance range. Check the resistance across the termi­nals of the heating element as described in the following table.
2. Insulation resistance.
Disconnect the wire leads to the heating element to be tested. Check the insulation resistance between the element terminal and cavity using a 500V - 100MΩ insulation tester. The insulation resistance should be more than 10 MΩ in the cold start.
If the results of above test 1 and/or 2 are out of above specifications, the heating element is probably faulty and should be replaced.
CARRY OUT 4R
CHECKS.
[13] Procedure M: CONTROL PANEL ASSEMBLY TEST
The control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper main­tenance can not be performed with only a voltmeter and ohmmeter.
In this service manual, the control panel assembly is divided into two units, Control Unit and Jog and Switch Unit, and also the control unit is divided into two units, CPU unit and Power unit, and troubleshooting by replacement is described according to the symptoms indicated.
1. Jog and Switch Unit Note: Check Jog and Switch unit wire harness connection before replacement.
The following symptoms indicate a defective Jog and Switch unit. Replace the Jog and Switch unit.
1) Tact switch
a) When touching the buttons, a certain button produces no signal at all.
MEASURING POINT INDICATION OF OHMMETER Between N and L Approx. 680 kΩ Between terminal N and WHITE Short circuit Between terminal L and RED Short circuit
Table: Resistance of heater
Parts name Resistance
Grill heating elements GH
(Top) Approximately 37.4 Ω -39.7Ω [(18.7Ω - 19.85Ω) x 2 ]
Convection heating elements CH
Approximately 34.09 Ω - 36.72Ω
F2: F8A
F1
20A
WHT
RED
R1
R2
N
Cx
Cy
L
L
L
L (min) Cx ± 20% Cy ± 20% R1 R2
1.0mH 0.22 uF 4700pF 10 M 680k
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b) When touching the buttons, sometimes a button produces no signal.
2) Potentiometer
a) When rotating the potentiometer, the cooking mode can not be selected.
3) Encoder
a) When rotating the encoder, the cooking time or the weight of food can not be entered.
2. Control Panel
The following symptoms indicate a defective control unit. Before replacing the control unit, perform the Jog and Switch unit test (Procedure N) to determine if control unit is faulty.
1) In connection with buttons
a) When touching the buttons, a certain group of buttons do not produce a signal.
b) When touching the buttons, no buttons produce a signal.
2) In connection with indicators
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light up.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
3) 2-3 Other possible troubles caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
d) Proper temperature measurement is not obtained.
[14] Procedure N: JOG AND SWITCH UNIT TEST
If the display fails to clear when the STOP button (tact switch SW13) is depressed, first ver­ify the wire harness is marking good contact, verify that the door sensing switch (stop switch) operates properly; that is the contacts are closed when the door is closed and open when the door is open. If the door sensing switch (stop switch) is good, disconnect the wire harness that connects the Jog and Switch unit to the control unit and make sure the door sensing switch is closed (either close the door or short the door sensing switch connecter). Use the Jog and Switch unit matrix indicated on the control panel schematic and place a jumper wire between the pins that correspond to the STOP button (tact switch SW13) mark­ing momentary contact. If the control unit responds by clearing with a beep the Jog and Switch unit is faulty and must be replaced. If the control unit does not respond, it is a faulty and must be replaced. If a specific button does not respond, the above method may be used (after clearing the control unit) to determine if the control unit or Jog and Switch unit is at fault.
CARRY OUT 4R
CHECKS.
J-6 J-5 J-2 J-1
J-3J-4J-8 J-7J-12 J-9J-11 J-10J-13
VR1
RSW1
A
B
3
1
2
C
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
SW9
SW10
SW13
SW12
SW11
SWITCH UNIT
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[15] Procedure O: RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 1 and 3 of the 4 pin connector (E) on the control unit with an A.C. voltmeter. The meter should indicate 230 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill operation, convection operation or dual operation.
DC. voltage indicated ................................... Defective relay.
DC. voltage not indicated ............................. Check diode which is connected to the relay coil. If diode is good, control unit is defective.
CARRY OUT 4R
CHECKS.
[16] Procedure P: PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD (PWB) IS OPEN
To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit on the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given below for repair.
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D
CHECKS.
NOTE: *At the time of these repairs, make a visual inspection of the varistor for burn-
ing damage and examine the transformer with tester for the presence of layer short circuit (check primary coil resistance).
If any abnormal condition is detected, replace the power unit.
CARRY OUT 4R
CHECKS.
RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 APPROX. 18.0V D.C. Oven lamp / Turntable motor RY2 APPROX. 18.0V D.C. High voltage transformer RY3 APPROX. 24.0V D.C. Grill (Top) heating element RY4 APPROX. 24.0V D.C. Convection heating element RY5 APPROX. 24.0V D.C. Fan motor RY6 APPROX. 24.0V D.C. Touch control transformer RY7 APPROX. 24.0V D.C. Convection motor RY8 APPROX. 24.0V D.C. Damper motor
STEPS OCCURRENCE CAUSE OR CORRECTION
1
The rated AC voltage is not present between Pin No. 1 and 3 of the 4-pin connector (E).
Check supply voltage and oven power cord.
2 The rated AC voltage is present at primary side of low voltage transformer.
Low voltage transformer or secondary circuit defective. Check and replace power unit.
3 Only pattern at “a” is broken. *Insert jumper wire J1 and solder.
4 Pattern at “a” and “b” are broken.
Replace power unit. (CARRY OUT 3D
CHECKS BEFORE
REPAIR)
(J1)
(J2)
9
1
7
CN-E
CN - A
VRS1
a
c
d
b
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Service Manual
CHAPTER 9. TOUCH CONTROL PANEL ASSEMBLY
[1] OUTLINE OF TOUCH CONTROL PANEL
The control section consists of the following units as shown in the con­trol panel circuit.
(1) Jog and Switch Unit
(2) Control Unit (The Control unit consists of Power unit and CPU unit.)
The principal functions of these units and signals communicated among them are explained below.
1. Jog and Switch Unit
1) Tact switch circuit
The jog and switch unit is composed of a matrix, signals generated in the LSI are sent to the jog and switch unit from P10, P11, P12, P13, P14, P15, P16 and P17. When a tact switch pad is touched, a signal is completed through the jog and switch unit and passed back to the LSI through P70, P71, P72 and P73 to perform the function that was requested.
2) Encoder
The encoder converts the signal generated by LSI into the pulse signal, and the pulse signal is returned to the LSI.
3) Potentiometer circuit
The circuit makes setting of the cooking mode by variable resis­tance.
2. Control Unit
Control unit consists of LSI, power source circuit, synchronizing signal circuit, ACL circuit, buzzer circuit, relay circuit, temperature measure­ment circuit, indicator circuit and back light circuit.
1) LSI
This LSI controls the temperature measurement signal, tact switch strobe signal, relay driving signal for oven function and indicator signal.
2) Power Source Circuit
This circuit generates voltage necessary in the control unit.
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in order to com­pose a basic standard time in the clock circuit. It accompanies a very small error because it works on commercial frequency.
4) ACL
A circuit to generate a signal which resets the LSI to the initial state when power is supplied.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit audible sounds (key touch sound and completion sound).
6) Door Sensing Switch (Stop Switch)
A switch to “tell” the LSI if the door is open or closed.
7) Relay Circuit
To drive the magnetron, grill heating element, convection heating element, convection motor, fan motor, turntable motor, damper motor, touch control transformer and light the oven lamp.
8) Back Light Circuit
A circuit to drive the back light (Light emitting diodes LD10 - LD19).
9) Indicator Circuit
This circuit consists 40-segments and 16-common electrodes using a Liquid Crystal Display.
The Liquid Crystal Display (LCD) is drive by LCD driver IC3.
10)Temperature Measurement Circuit: (OVEN THERMISTOR)
The temperature in the oven cavity is sensed by the thermistor. The variation of resistance according to sensed temperature is detected by the temperature measurement circuit and the result applied to LSI. The LSI uses this information to control the relay and display units.
11)Damper Switch
A switch to tell the LSI if the damper is open or close.
[2] SERVICING FOR TOUCH CONTROL PANEL
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the circuits. When han­dling these parts, the following precautions should be strictly followed. CMOS LSI have extremely high impedance at its input and output ter­minals. For this reason, it is easily influenced by the surrounding high voltage power source, static electricity charge in clothes, etc., and sometimes it is not fully protected by the built-in protection circuit.
In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap them in aluminium foil. Also wrap PW boards containing them in aluminium foil.
2) When soldering, ground the technician as shown in the figure and use grounded soldering iron and work table.
2. Servicing of Touch Control Panel
We describe the procedures to permit servicing of the touch control panel of the microwave oven and the precautions you must take when doing so. To perform the servicing, power to the touch control panel is available either from the power line of the oven itself or from an exter­nal power source.
1. Servicing the touch control panel with power supply of the
oven:
CAUTION: THE HIGH VOLTAGE TRANSFORMER OF THE MICRO-
WAVE OVEN IS STILL LIVE DURING SERVICING AND PRESENTS A HAZARD.
Therefore, before checking the performance of the touch control panel,
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.
Symbol Voltage Application
VC -5.2V LSI(IC1)
appro x. 1M o hm
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9 – 2
6) After that procedure, re-connect the power supply cord.
After checking the performance of the touch control panel,
1) Disconnect the power supply cord.
2) Open the door and block it open.
3) Re-connect the leads to the primary of the power transformer.
4) Re-install the outer case (cabinet).
5) Re-connect the power supply cord after the outer case is installed.
6) Run the oven and check all functions.
a) On some models, the power supply cord between the touch
control panel and the oven itself is so short that the two can't be separated. For those models, check and repair all the controls (sensor-related ones included) of the touch control panel while keeping it connected to the oven.
b) On some models, the power supply cord between the touch
control panel and the oven proper is long enough that they may be separated from each other. For those models, therefore, it is possible to check and repair the controls of the touch control panel while keeping it apart from the oven proper; in this case you must short both ends of the door sensing switch (on PWB) of the touch control panel with a jumper, which brings about an operational state that is equivalent to the oven door being closed. As for the sensor-related controls of the touch control panel, checking them is possible if the dummy resistor(s) with resistance equal to that of the controls are used.
2. Servicing the touch control panel with power supply from an
external power source:
Disconnect the touch control panel completely from the oven proper, and short both ends of the door sensing switch (on PWB) of the touch control panel, which brings about an operational state that is equivalent to the oven door being closed. Connect an exter­nal power source to the power input terminal of the touch control panel, then it is possible to check and repair the controls of the touch control panel; it is also possible to check the sensor-related controls of the touch control panel by using the dummy resistor(s).
3. Servicing Tools
Tools required to service the touch control panel assembly.
1) Soldering iron: 60W
(It is recommended to use a soldering iron with a grounding termi­nal.)
2) Oscilloscope: Single beam, frequency range: DC - 10MHz type or more advanced model.
3) Others: Hand tools
4. Other Precautions
1) Before turning on the power source of the control unit, remove the aluminium foil applied for preventing static electricity.
2) Connect the connector of the key unit to the control unit being sure that the lead wires are not twisted.
3) After aluminium foil is removed, be careful that abnormal voltage due to static electricity etc. is not applied to the input or output ter­minals.
4) Attach connectors, electrolytic capacitors, etc. to PWB, making sure that all connections are tight.
5) Be sure to use specified components where high precision is required.
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Service Manual
CHAPTER 10. PRECAUTIONS FOR USING LEAD-FREE SOLDER
1. Employing lead-free solder
The “Main PWB” of this model employs lead-free solder. This is indicated by the “LF” symbol printed on the PWB and in the service manual. The suffix letter indicates the alloy type of the solder.
Example:
2. Using lead-free wire solder
When repairing a PWB with the “LF” symbol, only lead-free solder should be used. (Using normal tin/lead alloy solder may result in cold soldered joints and damage to printed patterns.)
As the melting point of lead-free solder is approximately 40°C higher than tin/lead alloy solder, it is recommend that a dedicated bit is used, and that the iron temperature is adjusted accordingly.
3. Soldering
As the melting point of lead-free solder (Sn-Ag-Cu) is higher and has poorer wettability, (flow), to prevent damage to the land of the PWB, extreme care should be taken not to leave the bit in contact with the PWB for an extended period of time. Remove the bit as soon as a good flow is achieved. The high content of tin in lead free solder will cause premature corrosion of the bit. To reduce wear on the bit, reduce the temperature or turn off the iron when it is not required.
Leaving different types of solder on the bit will cause contamination of the different alloys, which will alter their characteristics, making good soldering more difficult. It will be necessary to clean and replace bits more often when using lead-free solder. To reduce bit wear, care should be taken to clean the bit thoroughly after each use.
Indicates lead-free solder of tin, silver and copper
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Service Manual
CHAPTER 11. COMPONENT REPLACEMENT AND ADJUSTMENT PROCE-
DURE
[1] BEFORE OPERATING
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result in severe, possibly fatal, electric shock.
(Example)
High Voltage Capacitor, High Voltage Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage fuse, High Voltage Harness etc..
WARNING:
Avoid possible exposure to microwave energy. Please follow the instructions below before operating the oven.
1) Disconnect the power supply cord.
2) Visually check the door and cavity face plate for damage (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;
1) Door does not close firmly.
2) Door hinge, support or latch hook is damaged.
3) The door gasket or seal is damaged.
4) The door is bent or warped.
5) There are defective parts in the door interlock system.
6) There are defective parts in the microwave generating 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.
To prevent an electric shock, take the following manners.
1. Before wiring,
1) Disconnect the power supply cord.
2) Open the door and block it open.
3) Discharge the high voltage capacitor and wait for 60 seconds.
2. Don't let the wire leads touch to the following parts;
1) High voltage parts:
Magnetron, High voltage transformer, High voltage capacitor and High voltage rectifier assembly.
2) Hot parts:
Grill heating element, Convection heating element, Oven lamp, Magnetron, High voltage transformer and Oven cavity.
3) Sharp edge:
Bottom plate, Oven cavity, Waveguide flange, Chassis support and other metallic plate.
4) Movable parts (to prevent a fault)
Fan blade, Fan motor, Switch, Turntable motor, Convection motor, convection fan and cooling fan.
3. Do not catch the wire leads in the outer case cabinet.
4. Insert the positive lock connector certainly until its pin is locked. And make sure that the wire leads should not come off even if the wire leads is pulled.
5. To prevent an error function, connect the wire leads correctly, refer­ring to the Pictorial Diagram.
Please refer to ‘OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS’, when carrying out any of the following removal proce­dures:
[2] OUTER CASE REMOVAL
To remove the outer case, procedure as follows.
1. Disconnect the oven from power supply.
2. Open the oven door and wedge it open.
3. Remove the one (1) screw holding the air duct to the oven cavity rear plate.
4. Remove the air duct.
5. Remove the nine (9) screws from rear and along the side edge of case.
6. Slide the entire case back about 3 cm to free it from retaining clips on the cavity face plate.
7. Lift the entire case from the oven.
8. Discharge the H.V. capacitor before carrying out any further work.
9. Do not operate the oven with the outer case removed.
NOTE: Step 1, 2 and 8 form the basis of the 3D
checks.
CAUTION: DISCHARGE HIGH VOLTAGE CAPACITOR BEFORE
TOUCHING ANY OVEN COMPONENT OR WIRING.
[3] 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. Disconnect the filament lead of the high voltage transformer and the high voltage wire of the high voltage transformer from the high voltage capacitor.
3. Disconnect the high voltage wire from the magnetron.
WARNING AGAINST HIGH VOLTAGE:
WARNING FOR WIRING
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4. Remove one (1) screw holding earth side terminal of the high volt­age rectifier assembly to the base plate through the capacitor holder.
5. Release the capacitor holder from the base plate.
6. Remove the high voltage capacitor from the capacitor holder.
7. Disconnect the high voltage rectifier assembly from the high volt­age capacitor.
8. Now, the high voltage rectifier assembly and the high voltage capacitor should be free.
CAUTION: WHEN REPLACING HIGH VOLTAGE RECTIFIER
ASSEMBLY, ENSURE THAT THE CATHODE (EARTH) CONNECTION IS SECURELY FIXED TO THE BASE PLATE THROUGH THE CAPACITOR HOLDER WITH AN EARTHING SCREW.
[4] HIGH VOLTAGE TRANSFORMER REMOVAL
To remove the components, proceed as follows.
1. CARRY OUT 3D
CHECKS.
2. Disconnect the main wire harness from the high voltage trans­former.
3. Disconnect the filament leads and high voltage wire of high voltage transformer from high voltage capacitor and the magnetron.
4. Remove the two (2) screws holding the transformer to the base plate.
5. Remove the transformer.
6. Now the high voltage transformer is free.
[5] MAGNETRON REMOVAL
1. CARRY OUT 3D CHECKS.
2. Disconnect the H.V. wire and filament lead of the transformer from the magnetron.
3. Carefully remove two (2) screws holding the magnetron to the waveguide, when removing the screws hold the magnetron to pre­vent it from falling.
4. Remove the one (1) screw holding the magnetron to the chassis support.
5. Remove the magnetron from the waveguide with care so the mag­netron antenna is not hit by any metal object around the antenna.
6. Now, the magnetron is free.
CAUTION: CAUTION: WHEN REPLACING THE MAGNETRON, BE
SURE THE R.F. GASKET IS IN PLACE AND THE MAG­NETRON MOUNTING SCREWS ARE TIGHTENED SECURELY.
[6] CONTROL PANEL ASSEMBLY REMOVAL
1. CARRY OUT 3D CHECKS.
2. Disconnect the wire leads and the connectors from the power unit.
3. Remove the one (1) screw holding the control panel to the oven cavity face plate.
4. Remove the one (1) screw holding the earth wire to the oven cavity face plate.
5. Lift up the control panel assembly and pull it forward.
Now the control panel assembly is free.
Jog and Switch unit
6. Disconnect the connector CN-G from the CPU unit.
7. Remove the four (4) screws holding the power unit to the control panel.
8. Remove the one (1) screw holding the LCD holder to the control panel.
9. Remove the control unit assembly (CPU unit and Power unit) from the control panel.
10.Remove the seven (7) screws holding the jog and switch unit to the control panel.
11.Remove the jog and switch unit from the control panel.
12.Now, the jog and switch unit is free.
[7] FAN MOTOR REREPLACEMENT
1. REMOVAL
1. CARRY OUT 3D CHECKS.
2. Remove the one (1) screw holding the noise filter to the chassis support.
3. Release the noise filter from the tabs of the fan duct.
4. Remove the three(3) screw holding the chassis support to the oven cavity front flange, back plate, and the magnetron.
5. Remove the chassis support from the oven cavity.
6. Disconnect the wire leads from the fan duct.
7. Remove the one (1) screw holding the fan duct to the back plate.
8. Release the tabs of the fan duct from back plate.
9. Remove the fan duct from the oven.
10.Remove the fan blade from the fan motor shaft according to the fol­lowing procedure.
i) Hold the edge of the rotor of the fan motor by using a pair of
groove joint pliers.
CAUTION: • Make sure that no swarf from the rotor enters the gap
between the rotor & stator of the fan motor.
• Avoid touch the coil of the fan motor with the pliers as the coil may become cut or damaged.
• Avoid deforming the bracket whilst using the pliers.
ii) Remove the fan blade assembly from the shaft of the fan motor
by pulling and rotating the fan blade with your hand.
iii) Now, the fan blade is free.
CAUTION: Do not re-use the removed fan blade as the fixing hole may
be oversize.
11.Remove the two (2) screws holding the fan motor to the fan duct.
12.Now, the fan motor is free.
2. INSTALLATION
1. Install the fan motor to the fan duct with the two (2) screws and nuts.
2. Install the fan blade to the fan motor shaft according to the following procedure.
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i) Hold the centre of the bracket which supports the shaft of the
fan motor on a flat table.
ii) Apply the screw lock tight into the hole (for shaft) of the fan
blade.
iii) 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 when installing because the
bracket may be deformed.
• Make sure that the fan blade rotates smoothly after installation.
• Make sure that the axis of the shaft is not slanted.
3. Insert the tabs of the fan duct to the back plate.
4. Install the fan duct to the back plate with the one (1) screw.
5. Re-install the chassis support to the oven cavity with the four (4) screws.
6. Install the noise filter to the fan duct and the chassis support with the one (1) screw.
7. Re-connect the wire leads to the fan motor.
[8] TURNTABLE MOTOR REPLACEMENT
1. REMOVAL
1. Disconnect the oven from the power supply.
2. Remove the turntable and roller stay from the oven cavity.
3. Turn the oven over.
4. Cut the three (3) bridges holding the turntable motor cover to the base plate with cutting pliers as shown in Figure C-1(a).
CAUTION: DO NOT DROP THE TURNTABLE MOTOR COVER INTO
THE OVEN AFTER CUTTING THE BRIDGES. BECAUSE IT WILL DAMAGE 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 base plate.
6. Disconnect the wire leads from the turntable motor.
7. Remove the two (2) screws holding the turntable motor to the oven cavity back plate.
8. Remove the turntable motor from the turntable motor angle. Now, the turntable motor is free.
2. REINSTALL
1. Remove the any sharp edges on the turntable motor cover and the base plate with the cutting pliers.
2. Re-install turntable motor by locating shaft onto coupling to the oven cavity base plate with the two (2) screws.
3. Re-connect the wire leads to the turntable motor.
4. Insert the one (1) tab of the turntable motor cover into the slit of the base plate as shown in Figure C-1(b).
5. Re-install the turntable motor cover to the base plate with the screw (XHPS740P08K00) as shown in Figure C-1(b).
Figure C-1(a) Turntable Motor Cover Replacement
Figure C-1(b) Turntable Motor Cover reinstall
[9] CONVECTION MOTOR AND CONVECTION HEATING ELEMENT REMOVAL
1. CONVECTION UNIT ASSEMBLY REMOVAL
1. CARRY OUT 3D CHECKS.
Now, the outer case cabinet and the air duct should have been removed.
2. Remove the one (1) screw holding the earth wire of the power sup­ply cord to the back plate.
3. Release the power supply cord from the back plate.
4. Remove the two (2) screws holding the rear barrier to the base plate.
5. Release the three (3) tabs of rear barrier from the base plate. And remove the rear barrier.
6. Remove the one (1) screw holding the back plate to the base plate.
7. Remove the one (1) screw holding the chassis support to the back plate.
8. Remove the one (1) screw holding the back plate to the air intake duct.
Gap
Rotor
Bracket
Stator
Groove joint pliers
Coil
Shaft
Axis
Stator
Rotor
These are the positions that should be pinched with pliers.
Shaft
Table
Center of bracket
Rear View
Side View
Cutting pliers
Turntable motor cover
Bridges
Base plate
Turntable motor cover
Tab
Screw: XHPS740P08K00
Base plate
Slit
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9. Remove the two (2) screws holding the back plate to the convec­tion duct.
10.Remove the back plate from the oven cavity.
11.Disconnect the wire leads from the convection heating elements, convection motor and thermal cut-out.
12.Remove the one (1) screw holding the convection duct to the oven cavity back plate from outside of the oven cavity.
13.Remove the seven (7) screws holding the convection duct to the oven cavity back plate from inside of the oven cavity.
14.Lift up the convection duct and release the three (3) tabs of the oven cavity back plate from the convection duct.
15.Now, the convection unit assembly is free.
2. CONVECTION HEATING ELEMENT REMOVAL
1. Remove the convection unit assembly refer to the “CONVECTION UNIT ASSEMBLY REMOVAL”.
2. Remove the two (2) screws holding the convection heating element to the convection duct.
3. Remove the one (1) screw holding the convection heater angle to the convection duct.
4. Remove the one (1) screw holding the convection heater angle and the air separate angle D to the convection duct.
5. Remove the one (1) screw holding the convection heater angle A to the convection duct.
6. Remove the convection heating element from the convection duct.
7. Now, the convection heating element is free.
3. CONVECTION MOTOR REMOVAL
1. Remove the convection unit assembly refer to the “CONVECTION UNIT ASSEMBLY REMOVAL”.
2. Remove the one (1) nut and washer from the convection motor shaft.
3. Remove the convection fan from the convection motor shaft.
4. Remove the pipe from the convection motor shaft.
5. Remove the two (2) screws holding the convection motor angle to the convection duct.
6. Remove the cooling fan from the convection motor shaft.
7. Remove the two (2) screws holding the convection motor to the convection motor angle.
8. Remove the one (1) ring from the convection motor shaft.
9. Now, the convection motor is free.
[10] POSITIVE LOCK® CONNECTOR REMOVALPOSITIVE LOCK CONNECTOR REMOVAL­POSITIVE LOCK CONNECTOR REMOVALPOSITIVE LOCK CONNECTOR REMOVALPOSITIVE LOCK CONNECTOR REMOVALPOSITIVE LOCK CONNECTOR REMOVALPOSITIVE LOCK CONNECTOR REMOVALPOSITIVE LOCK CONNECTOR REMOVALPOSITIVE LOCK CON­NECTOR REMOVALPOSITIVE LOCK CONNECTOR REMOVALPOSITIVE LOCK CONNECTOR REMOVALPOSITIVE LOCK CONNECTOR REMOVAL
1. CARRY OUT 3D CHECKS.
2. Push the lever of positive lock
®
connector.
3. Pull down on the positive lock
®
connector.
CAUTION: WHEN CONNECTING THE POSITIVE LOCK
®
CONNEC­TORS TO THE TERMINALS, CONNECT THE POSITIVE LOCK
®
SO THAT THE LEVER FACES YOU.
Figure C-2. Positive lock®, connector
[11] OVEN LAMP SOCKET REMOVAL
1. CARRY OUT 3D CHECKS.
2. Remove the wire leads as Positive lock
®
connector removal above.
3. Lift up the oven lamp from its retaining clips by pushing the tab of the air intake duct.
4. Now, the oven lamp is free.
Figure C-3. Oven lamp
[12] POWER SUPPLY CORD REPLACEMENT
1. REMOVAL
1. CARRY OUT 3D CHECKS.
Terminal
Push
Pull down
1
2
Lever
Positive lock¨ connector
Lock
Socket
Bulb
Page 31
R939(W)
11 – 5
2. Remove the one (1) screw holding the green/yellow wire to the back plate.
3. Disconnect the leads of the power supply cord from the noise filter, referring to the Figure C-4(a).
4. Release the power supply cord from the rear cabinet.
5. Now, the power supply cord is free.
Figure C-4 (a) Replacement of Power Supply Cord
2. REINSTALL
1. Insert the moulding cord stopper of power supply cord into the square hole of the power angle, referring to the Figure C-4(b).
2. Install the earth wire lead of power supply cord to the back plate with one (1) screw and tight the screw.
3. Connect the brown and blue wire leads of power supply cord to the noise filter correctly, referring to the Pictorial Diagram.
Figure C-4(b). Power Supply Cord Replacement
[13] GRILL HEATING ELEMENTS REMOVAL
1. CARRY OUT 3D CHECKS.
2. Disconnect wire leads from the thermal cut-out (GRILL).
3. Remove the two (2)screws holding the two (2) terminals of the main wire harness to the two (2) grill heating elements.
4. Remove the one (1) screw holding the exhaust duct to the oven cavity top plate.
5. Remove the exhaust duct from the oven cavity top plate.
6. By pushing the two (2) tabs holding the grill reflector to the oven cavity top plate, slide the grill reflector toward the magnetron. And then lift up the grill reflector and remove it.
7. Remove the one (1) screw holding the grill heater angle to the grill heater reflector.
8. Straighten the two (2) tabs of the grill heater angle and remove the grill heater angle from the grill reflector.
9. Remove the two (2) screws holding the earth plate to the two (2) grill heating elements.
10.Remove the two (2) grill heating elements from the grill reflector.
11.Now, the grill heating elements are free.
[14] MONITORED LATCH SWITCH, MONITOR SWITCH AND STOP SWITCH REMOVAL
1. CARRY OUT 3D CHECKS.
2. Remove the control panel assembly referring to “CONTROL PANEL ASSEMBLY REMOVAL”.
3. Disconnect the leads from all switches.
4. Remove the two (2) screws holding the latch hook to the oven cav­ity.
5. Remove the latch hook.
6. Remove the switch(es) from the latch hook by pushing the retaining tab backwards slightly and turning the switch(es) on the post.
7. Now the switch(es) is free
Figure C-5. Switches
[15] MONITORED LATCH SWITCH, STOP SWITCH AND MONITOR SWITCH ADJUSTMENT
1. Adjustment
If the monitored latch switch, stop switch and monitor switch do not operate properly due to a mis-adjustment, the following adjustment should be made.
1. CARRY OUT 3D
CHECKS.
2. Loosen the two (2) screws holding the latch hook to the oven cavity front flange.
3. With the door closed, 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 less than 0.5 mm.
Power supply cord
Back plate
Blue wire
Brown wire
Green/ Yellow wire
Noise filter
WHIT
RED
F2
F1
TP
N
L
TL
Power supply cord
Back plate
Moulding cord stopper
Square hole
SW2: Stop switch
SW3: Monitor switch
SW1: Monitored
latch switch
Tab
Post
Post
Page 32
R939(W)
11 – 6
The horizontal position of the latch hook should be placed where the monitor switch has activated with the door closed. The vertical position of the latch hook should be placed where the monitored latch switch and stop switch have activated with the door closed.
4. Secure the screws with washers firmly.
5. Make sure of the all switches operation. If the latch head has not pushed the plungers of the monitor switch with door closed, adjust the latch hook position. At that time, the latch head should have pushed the plungers of the monitored latch switch and stop switch. If the latch head has not pushed the plungers of the monitored latch switch and stop switch with door closed, loose two (2) screws hold­ing latch hook to oven cavity front flange and adjust the latch hook position.
2. After adjustment, make sure of following.
1. 1. In and out play of door remains less than 0.5 mm when latched position. First check the latch hook position, pushing and pulling upper portion of the door toward the oven face. Then check the lower latch hook position, pushing and pulling lower portion of the door toward the oven face. Both results (play of the door) should be less than 0.5mm.
2. The contacts (COM-NO) of the stop switch and the monitored latch switch open within 1.8mm gap between right side of cavity face plate and door when door is opened.
3. When the door is closed, the contacts (COM-NO) of the stop switch close.
4. When the door is closed the contacts (COM-NC) of the monitor switch and monitored latch switch open. And the contacts (COM­NO) of their switches close.
5. Re-install outer case and check for microwave leakage around the door with an approved microwave survey meter. (Refer to Micro­wave Measurement Procedure.)
Figure C-6 Latch Switches Adjustment
[16] DOOR REPLACEMENT
1. REMOVAL
1. Disconnect the oven from the power supply.
2. Push the door slightly.
3. Remove the door stopper from the choke cover.
4. Lift the door upwards.
5. Now, door assembly is free from oven cavity.
6. Insert an putty knife (thickness of about 0.5mm) into the gap between the choke cover and door frame as shown in Figure C-7 to free engaging parts.
7. Release choke cover from door panel.
8. Now choke cover is free.
Figure C-7. Door Disassembly
DOOR PANEL
9. Remove the eight (8) screws holding the door panel to the door frame.
10.Now, door panel is free.
CAUTION: DO NOT DEFORM OR WARP THE TEETH OF COMB OF
THE DOOR PANEL TO PREVENT MICROWAVE RADIA­TION EMISSION FROM THE DOOR.
LATCH HEAD AND SPRING
11.Slide latch head upward and remove it from door frame with releas­ing latch spring from door frame and latch head.
12.Now, latch head and latch spring are free.
DOOR HANDLE AND FRONT DOOR GLASS
13.Remove the two (2) screws holding the door handle and the glass stopper to the door frame.
14.Remove the door handle and the glass stopper from the door frame.
15.Slide the front door glass leftward and then slide downwards to release the tabs holding it.
16.Now, the front door glass is free
2. REINSTALLATION
1. Re-install the front door glass to the door frame as follows.
1) Insert the upper edge of the front door glass into the tabs of the
door frame.
2) Slide the front door glass downwards and insert the lower edge
of the front door glass into the tabs of the door frame.
3) Slide the front door glass rightwards and insert the right edge of
the front door glass into the tabs of the door frame.
2. Re-install the door handle and the glass stopper to the door frame as follows.
1) Insert the door handle and the glass stopper to the door frame.
2) Hold the door handle and the glass stopper to the door frame
with the two (2) screws.
3. Re-install the latch spring to the latch head. Re-install the latch spring to the door frame. Re-install latch head to door frame.
4. Re-install door panel to door frame.
Latch hook
Door
SW2: Stop switch
Latch Heads
SW3: Monitor switch
SW1: Monitored
latch switch
Tab
Putty knife
Choke cover
Door frame
Door stopper
Page 33
R939(W)
11 – 7
5. Hold the door panel to the door frame with eight (8) screws.
6. Re-install choke cover to door panel by clipping into position.
7. Locate door panel hinge pins into cavity hinge location holes.
8. Re-install the door stopper to the chock cover.
NOTE: After any service to the door;
1) Make sure that the monitor switch, monitored latch
switch and stop switch are operating properly. (Refer to chapter “Test Procedures”.).
2) An approved microwave survey meter should be used
to assure compliance with proper microwave radiation emission limitation standards. (Refer to Microwave Measurement Procedure.)
3. 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 Microwave Measurement Procedure.)
NOTE: The door on a microwave oven is designed to act as an elec-
tronic 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 light­tight. Therefore, occasional appearance of moisture, light or sensing of gentle warm air movement around oven door is not abnormal and do not of themselves, indicate a leakage of microwave energy from oven cavity.
Figure C-8. Door Replacement
Upper oven hinge
Lower oven hinge
Lower oven hinge
Pin
Door assembly
Pin
Page 34
R939(W)
12 – 1
R939(W)
Service Manual
CHAPTER 12. MICROWAVE MEASUREMENT
After adjustment of door latch switches, monitor switch and door are completed individually or collectively, 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/cm
2
at any point 5cm or more from external surface of the oven.
PREPARATION FOR TESTING
Before beginning the actual test for leakage, proceed as follows;
1. Make sure that the test instrument is operating normally as specified in its instruction booklet.
Important:
Survey instruments that comply with the requirement for instrumentations as prescribed by the performance standard for microwave ovens must be used for testing.
Recommended instruments are:
NARDA 8100
NARDA 8200
HOLADAY HI 1500
SIMPSON 380M
2. Place the oven tray into the oven cavity.
3. Place the load of 275 ±15ml of water initially at 20 ±5°C in the centre 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 important not only to protect the oven, but also to insure 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 cool water.
5. Move the probe slowly (not faster that 2.5cm/sec.) along the gap.
6. The microwave radiation emission should be measured at any point of 5cm or more from the external surface of the oven.
Microwave leakage measurement at 5 cm distance
mW cm
2
mW cm
2
Page 35
R939(W)
13 – 1
R939(W)
Service Manual
CHAPTER 13. TEST DATA AT A GLANCE
PARTS SYMBOL VALUE / DATA
Fuse F1 20A 250V Fuse (Noise filter) F2 F8A Thermal cut-out TC1 125°C Off Thermal cut-out TC2, TC3 170°C Off / 155°C On Thermistor Approx. 359.9 kΩ - 152 kΩ at 20°C - 30°C Grill heating element GH Approx. 37.4Ω - 39.7Ω [(18.7Ω - 19.85Ω) x 2] / Insulation resistance > 10MΩ Convection heating element CH Approx. 34.09Ω - 36.72Ω / Insulation resistance > 10MΩ Oven lamp OL 240 - 250V 25W High voltage capacitor C AC 2100V 1.16μF Magnetron MG Filament < 1Ω / Filament - chassis ohm High voltage transformer T Filament winding < 1Ω
Secondary winding Approx. 123Ω Primary winding Approx. 1.9Ω
WARNING: DISCONNECT THE PLUG WHEN MEASURING RESISTANCE
Page 36
R939(W)
14 – 1
R939(W)
Service Manual
CHAPTER 14. CIRCUIT DIAGRAMS
[1] Oven Schematic
Figure O-1(a) Oven Schematic-OFF Condition right after the oven is plugged in.
Figure O-1(b) Oven Schematic-OFF Condition when the oven door is opened.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. PLUGGED IN OVEN.
3. NOTHING APPEARS ON DIS PLAY.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. "SELECTED LANGUAGE” APPEARS ON DISPLAY.
NOTE: " " indicates components with potentials above 250V
OL
OVEN LAMP
CONVECTION MOTOR
DAMPER MOTOR
FAN MOTOR
TURNTABLE MOTOR
GRILL HEATING ELEMENTS
CONVECTION HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.16 uF
AC2100V
CONTROL UNIT
A7
D3D1
RY5
A3
E5 E7
E3 E1
A1
B2
B3
B4
C3
C1
B1
STOP SWITCH
DAMPER SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MAG.
THERMAL
CUT-OUT
CONV.
THERMAL
CUT-OUT
GRILL
THERMAL
CUT-OUT
MONITOR SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22 u/250V
FUSE
F8A
NOISE
FILTER
LN
230 V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
N.O.
N.C.
N.C.
N.O .
COM.
COM.
ASYMMETRIC RECTIFIER
RY6
RY7
RY8
RY1 RY2 RY3
RY4
FM
TTM
CM
DM
F1: FUSE 20A
F2:
TC1:
CH:
T:
C:
MG:
GH:
TC2:
TC3:
SW1:
SW3:
SW4: SW2:
A5
OL
OVEN LAMP
CONVECTION MOTOR
DAMPER MOTOR
FAN MOTOR
TURNTABLE MOTOR
GRILL HEATING ELEMENTS
CONVECTION HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.16 uF
AC2100V
CONTROL UNIT
A7
D3D1
RY5
A3
E5 E7
E3 E1
A1
B2
B3
B4
C3
C1
B1
STOP SWITCH
DAMPER SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MAG.
THERMAL
CUT-OUT
CONV.
THERMAL
CUT-OUT
MONITOR SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22 u/250V
FUSE
F8A
NOISE
FILTER
LN
230 V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
N.O.
N.C.
N.C.
N.O .
COM.
COM.
ASYMMETRIC RECTIFIER
RY6
RY7
RY8
RY1 RY2 RY3
RY4
FM
TTM
CM
DM
GRILL
THERMAL
CUT-OUT
F1: FUSE 20A
F2:
TC1:
CH:
T:
C:
MG:
GH:
TC2:
TC3:
SW1:
SW3:
SW4: SW2:
A5
Page 37
R939(W)
14 – 2
Figure O-1(c) Oven Schematic-OFF Condition after the oven door is closed.
Figure O-2 Oven Schematic-Microwave cooking Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED. 2 " . O" APPEARS ON DISPLAY.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. MICROWAVE MODE SET.
3. COOKING TIME SET.
4. STRAT BUTTON PRESSED.
OL
OVEN LAMP
CONVECTION MOTOR
DAMPER MOTOR
FAN MOTOR
TURNTABLE MOTOR
GRILL HEATING ELEMENTS
CONVECTION HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.16 uF
AC2100V
CONTROL UNIT
A7
D3D1
RY5
A3
E5 E7
E3 E1
A1
B2
B3
B4
C3
C1
B1
STOP SWITCH
DAMPER SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MAG.
THERMAL
CUT-OUT
CONV.
THERMAL
CUT-OUT
MONITOR SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680k/0.5W
0.22 u/250V
FUSE
F8A
NOISE
FILTER
LN
230 V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
N.O.
N.C.
N.C.
N.O .
COM.
COM.
ASYMMETRIC RECTIFIER
RY6
RY7
RY8
RY1 RY2 RY3
RY4
FM
TTM
CM
DM
GRILL
THERMAL
CUT-OUT
A5
F1: FUSE 20A
F2:
TC1:
CH:
T:
C:
MG:
GH:
TC2:
TC3:
SW1:
SW3:
SW4: SW2:
NOTE: " " indicates components with potentials above 250V
OL
OVEN LAMP
CONVECTION MOTOR
DAMPER MOTOR
FAN MOTOR
TURNTABLE MOTOR
GRILL HEATING ELEMENTS
CONVECTION HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.16 uF
AC2100V
CONTROL UNIT
A7
D3D1
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E5 E7
E3 E1
A1
B2
B3
B4
C3
C1
B1
STOP SWITCH
DAMPER SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MAG.
THERMAL
CUT-OUT
CONV.
THERMAL
CUT-OUT
MONITOR SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22 u/250V
FUSE
F8A
NOISE
FILTER
LN
230 V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
N.O.
N.C.
N.C.
N.O .
COM.
COM.
ASYMMETRIC RECTIFIER
RY6
RY7
RY8
RY1 RY2 RY3
RY4
FM
TTM
CM
DM
GRILL
THERMAL
CUT-OUT
F1:FUSE20A
F2:
TC1:
CH:
T:
C:
MG:
GH:
TC2:
TC3:
SW1:
SW3:
SW4: SW2:
A5
Page 38
R939(W)
14 – 3
Figure O-3 Oven Schematic-Grill cooking Condition (TOP GRILL mode)
Figure O-4 Oven Schematic-Convection Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. GRILL MODE SET.
3. COOKING TIME SET.
4. STRAT BUTTON PRESSED.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. CONVECTION MODE SET.
3. COOKING TIME SET.
4. CONVECTION TEMPERATURE SELECTED.
5. STRAT BUTTON PRESSED.
OL
OVEN LAMP
CONVECTION MOTOR
DAMPER MOTOR
FAN MOTOR
TURNTABLE MOTOR
GRILL HEATING ELEMENTS
CONVECTION HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.16 uF
AC2100V
CONTROL UNIT
A7
D3D1
RY5
A3
E5 E7
E3 E1
A1
B2
B3
B4
C3
C1
B1
STOP SWITCH
DAMPER SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MAG.
THERMAL
CUT-OUT
CONV.
THERMAL
CUT-OUT
MONITOR SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22 u/250V
FUSE
F8A
NOISE
FILTER
LN
230 V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
N.O.
N.C.
N.C.
N.O .
COM.
COM.
ASYMMETRIC RECTIFIER
RY6
RY7
RY8
RY1 RY2 RY3
RY4
FM
TTM
CM
DM
GRILL
THERMAL
CUT-OUT
A5
F1: FUSE 20A
F2:
TC1:
CH:
T:
C:
MG:
GH:
TC2:
NOTE: " " indicates components with potentials above 250V
OL
OVEN LAMP
CONVECTION MOTOR
DAMPER MOTOR
FAN MOTOR
TURNTABLE MOTOR
GRILL HEATING ELEMENTS
CONVECTION HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.16 uF
AC2100V
CONTROL UNIT
A7
D3D1
RY5
A3
E5 E7
E3 E1
A1
B2
B3
B4
C3
C1
B1
STOP SWITCH
DAMPER SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MAG.
THERMAL
CUT-OUT
CONV.
THERMAL
CUT-OUT
MONITOR SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22 u/250V
FUSE
F8A
NOISE
FILTER
LN
230 V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
N.O.
N.C.
N.C.
N.O .
COM.
COM.
ASYMMETRIC RECTIFIER
RY6
RY7
RY8
RY1 RY2 RY3
RY4
FM
TTM
CM
DM
GRILL
THERMAL
CUT-OUT
A5
F1: FUSE 20A
F2:
TC1:
CH:
T:
C:
MG:
GH:
TC2:
TC3:
SW1:
SW3:
SW4: SW2:
Page 39
R939(W)
14 – 4
Figure O-5(a) Oven Schematic-Dual cooking Condition (Microwave and Convection)
Figure O-5(b) Oven Schematic-Dual cooking Condition (Microwave and Grill)
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. DUAL1 MODE SET.
3. COOKING TIME SET.
4. MICROWAVE POWER LEVEL SET.
5. CONVECTION TEMPERATURE SELECTED.
6. STRAT BUTTON PRESSED.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. DUAL 2 MODE PAD TSET.
3. COOKING TIMESET.
4. MICROWAVE POWER LEVEL SET.
5. STRAT BUTTON PRESSED.
OL
OVEN LAMP
CONVECTION MOTOR
DAMPER MOTOR
FAN MOTOR
TURNTABLE MOTOR
GRILL HEATING ELEMENTS
CONVECTION HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.16 uF
AC2100V
CONTROL UNIT
A7
D3D1
RY5
A3
E5 E7
E3 E1
A1
B2
B3
B4
C3
C1
B1
STOP SWITCH
DAMPER SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MAG.
THERMAL
CUT-OUT
CONV.
THERMAL
CUT-OUT
MONITOR SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22 u/250V
FUSE
F8A
NOISE
FILTER
LN
230V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
N.O.
N.C.
N.C.
N.O .
COM.
COM.
ASYMMETRIC RECTIFIER
RY6
RY7
RY8
RY1 RY2 RY3
RY4
FM
TTM
CM
DM
GRILL
THERMAL
CUT-OUT
A5
F1:FUSE20A
F2:
TC1:
CH:
T:
C:
MG:
GH:
TC2:
TC3:
SW1:
SW3:
SW4: SW2:
NOTE: " " indicates components with potentials above 250V
OL
OVEN LAMP
CONVECTION MOTOR
DAMPER MOTOR
FAN MOTOR
TURNTABLE MOTOR
GRILL HEATING ELEMENTS
CONVECTION HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.16 uF
AC2100V
CONTROL UNIT
A7
D3D1
RY5
A3
E5 E7
E3 E1
A1
B2
B3
B4
C3
C1
B1
STOP SWITCH
DAMPER SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MAG.
THERMAL
CUT-OUT
CONV.
THERMAL
CUT-OUT
MONITOR SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22 u/250V
FUSE
F8A
NOISE
FILTER
LN
230V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
N.O.
N.C.
N.C.
N.O .
COM.
COM.
ASYMMETRIC RECTIFIER
RY6
RY7
RY8
RY1 RY2 RY3
RY4
FM
TTM
CM
DM
GRILL
THERMAL
CUT-OUT
A5
F1:FUSE20A
F2:
TC1:
CH:
T:
C:
MG:
GH:
C2:
Page 40
R939(W)
14 – 5
[2] Pictorial Diagram
Figure S-1. Pictorial Diagram
THERMAL
CUT-OUT(MAG)
THERMAL
CUT-OUT(CONV.)
OVEN LAMP
THERMAL
CUT-OUT(GRILL)
YLW
GRY
BLK
1 RED
2
3 WHT
4
5 GRY
6
7 YLW
COM
GRY
YLW
WHT
WHT
GRY
GRY
N.C.
N.O.
N.C.
COM.
COM.
N.O.
STOP
SWITCH
NO
COM
GRILL
HEATING ELEMENT
CONVECTION
HEATING ELEMENT
WHT
RED
WHT
BRN
BLU
RED
GRN
GRN
GRN
RED
TURNTABLE
MOTOR
DAMPER
MOTOR
T/C
TRANSFORMER
MONITOR
SWITCH
DAMPER
SWITCH
MONITORED
LATCH
SWITCH
WHT
YLW
BLK
RED
RED
RED
YLW
BLK
YLW
RED
RED
YLW
YLW
BLK
CN-A
CN-B
CN-D
BLK
NOISE FILTER
L
TP
F2
TL
RED
F1
WHT
N
BLK
RED
YLW
BLK
WHT
BLK
GRY
YLW
W
H
T
1 BLK
2
3 WHT
4
5
4
BLU
3
BRN
2 GRN
1 RED
1 BLU
2
3 BRN
4
5 ORG
6
7 RED
FAN
MOTOR
CONVECTION
MOTOR
WHT
RED
HIGH VOLTAGE COMPONENTS
G-Y
POWER SUPPLY
CORD
NEUTRAL
LIVE
EARTH
THERMISTOR
CN-B
1
1
1
1
151
4
13
15
3
4
1
RY2
RY4
RY3
CONTROL PANEL
CN-A
CN-E
RY5
RY7
1
1
7
CN-C
1
5
CN-5
CN-E
WH-1 WH-2
CN-1 CN-2
CN-F
CN-G
RY1
RY6
RY8
2
3
1
BLK
BLK
CN-C
MAGNETRON
Long Black Tube
Black Tube
Red wire
H.V.WIRE
H.V.
CAPACITOR
C:
H.V.
RECTIFIER
ASYMMETRIC
RECTIFIER
HIGH VOLTAGE
TRANSFORMER
RED
WHT
BRN
BLU
RED
WHT
RED
RED
RED
RED
BLK
RED
RED
RED
YLW
TC3:
SW4 :
TC2:
TC1:
GH:
CM:
CH:
FM:
DM:
OL:
SW2:
SW3:
SW1:
TTM:
MG:
T:
YLW
RED
Page 41
R939(W)
14 – 6
[3] Power Unit Circuit
Figure S-2. Power Unit Circuit
E1
WH1-4
WH1-3
WH1-6
WH1-9
WH1-5
WH1-8
WH1-7
WH1-1
WH1-2
WH2-1
WH1-n
WH1-10
WH1-12
WH1-13
WH1-14
WH1-15
WH1-11
C1
E3
E5
E7
T1
AC230V 50Hz
FAN MOTOR
OVEN THERMISTOR
GND
GND
R3 680 1w
Q1 2SB1238
R6 130 1w
Q2 2SB1238
Q3 KRC243M
R4 510 1w
D10 S1NB10
RY5
ab
c
d
C1
VRS1
(J1)
(J2)
D5
RY6
D6
RY7
D7
RY1
D1
R2
1.5k
ZD2
HZ20-1
ZD1
HZ16-1
RY4
D4
RY3
D3
RY2
D2
10G471K
C3
C2 1000 u/35v
C5
10 u/35v
C4 10 u/35v
R1 2.4k
R5 3.3k
SP1
VC
BUZZER
VR
VA
INT POWER
CONTROL
STOP SWITCH
DAMPER SWITCH
NC
CONVECTION MOTOR
DAMPER MOTOR
NC
CONVECTION HEATING ELEMENT
GRILL HEATING ELEMENT
HIGH VOLTAGE TRANSFORMER
STOP SWITCH
DAMPER SWITCH
OVEN LAMP TURNTABLE MOTOR
DOOR OPEN
CONTACT
A1
A3
A5
A7
D1
D5
B4
B3
B2
B1
NOTE 1. NOTE 2.
+
Ð
+
-
+
-
WH2-4
WH2-3
RY8
D8
D3
C3
: IF NOT SPECIFIED, 1/4W 5% 15P WIRE HARNESS
WH2-n
4P WIRE HARNESS
: IF NOT SPECIFIED, 0.1 F / 50V
: IF NOT SPECIFIED, 1SS270A
WH2-2
Page 42
R939(W)
14 – 7
[4] Control Unit Circuit
Figure S-3. CPU Unit Circuit
: IF NOT SPECIFIED 1/10W ±5%
: IF NOT SPECIFIED 1SS355
: IF NOT SPECIFIED 0.01 uF/25V
HIGH
VOLTAGE
TRANSFORMER
STOP
SWITCH
DAMPER
SWITCH
OVEN
THERMISTOR
NC
VC
VR
VA
BUZZER
POWER
CONTROL
DAMPER
MOTOR
FAN
MOTOR
CONVEC
MOTOR
CONVEC
HEATING
ELEMENT
GRILL
HEATING
ELEMENT
OVEN LAMP
TURNTABLE
MOTOR
INT
GND
NOTE :
ZD10
UDZ4.3B
GND
IC1
4MHz
P03
P02
P01
P00
P37
P36
P35
P34
P33
P32
P31 P30
P85 P84 P83 P82 P81 P80
VCC
VREF
AVSS AN7 AN6 AN5 AN4 AN3
C13
C12
C1-5
R10
1K
Q11
DTA143EKA
C14
60
55
75
70
CF1
(A)
(H)
(G)
(F)
(E)
(D)
(B)
65
P13
P12
P11
P10
P07
P06
P05
P04
P15
P14
50
45
SeeFig.S-5
See
Fig. S-5
See
Fig. S-4
C100
IC4
AT24C01A
(J10)(J11)
4.7K
(J12)(J13)
4.7K
(J14)(J15)
4.7K
(J16)(J17)
4.7K
(J18)(J19)
4.7K
(J20)(J21)
4.7K
(J22)(J23)
4.7K
See(KI5
See(KI5
See(KI5
(I)
(J)
(K)
(M)
(N)
(J)
C10 47uF/16V
(Q)
(P)
(R)
LD10 LD14LD13LD12LD11
LD19 LD15LD16LD17LD18
0.1㩷㫌F/50V
C1-9
(N)
C1-3
C1-6
C1-10
C2-2
C1-11
C2-4
C2-3
C1-8
ROTISS
C1-7
C1-15
C11
0.1uF/50V
C1-12
C1-13
C1-14
C1-1
C1-2
(Q)
(A)
(H)
(G)
(F)
(E)
(D)
(B)
(K)
R81
R83
R82
(P)
(M)
(R)
C1-4
15K430F
C80
C83
15K
R85
R84
4.7K
C2-1
R31
15K
C30
R30 4.7K
A1A2A0
GND
TS
VCC
SCL
SDA
Q10
2SA1037AK
Q30
DTA143EKA
DTA143EKA
DTA143EKA
DTA143EKA
DTA143EKA
DTA143EKA
Q21
Q20
Q23
Q24
Q25
Q26
Q27
Q28D20
D21
D30
DTA123JKA
DTA123JKA
DTA123JKA
D5
D6
R4
27
R5
4.7K
Q2
KTA1661
C20
0.1uF/50V
AN2 AN1
P87 P86
AN0
P77
P76
P75
P74
P73
P72
P70
P57
P55
P56
P54
P53
P52
P51
P50
P47
P45
P46
1
5
10
15
20
P71
INT0
CNVSS
RESET
P41
P40
XIN
XOUT
VSS
40
25
30
35
P27
P26
P25
P24
P23
P22
P21
P20
P44
INT1
P17
P16
C15
INT0
R55
4.7K
R56
1M
CN-C1
CN-C2
C16
0.1uF
50V
15PIN
4PIN
80
61
41
R11
4.7K
R12
4.7K
10K
R80
200KF
11.5KF
(I)
R13
1K
47K
R58
R48
47KR47
4.7K
R57
Page 43
R939(W)
14 – 8
[5] Indicator Circuit
Figure S-4. Indicator Circuit
COOK
VC1
VC2
VC3
VC4
VC5
CF
CE
CD
CC
CB
CA
COM8
COM9
COM10
COM11
COM12
COM13
COM14
COM15
COM16
SEG39
SEG38
SEG37
SEG36
SEG35
SEG29
SEG28
SEG27
SEG26
SEG25
SEG24
SEG23
SEG22
SEG21
SEG20
SEG19
SEG18
SEG17
SEG16
SEG15
SEG14
SEG13
SEF12
SEG11
SEG10
SEG8
SEG9
SEG7 SEG6 SEG5 SEG4 SEG3 SEG2 SEG1 SEG0
COM7 COM6 COM5 COM4 COM3 COM2 COM1 COM0
BZ
VSS OSC1 OSC2
VD1
OSC3 OSC4 VDD
RESET
TEST
VREF
R03
R02
R01
R00
P13
P11
P12
P10
P03
P02
P01
P00
K03
K02
K01
K00
SEG30
SEG31
SEG32
SEG33
SEG34
SEG34
SEG33
SEG32
SEG31
SEG30
SEG29
SEG28
SEG27
SEG26
SEG25
SEG24
SEG23
COM16
COM15
COM14
COM13
COM12
COM11
COM10
COM9
SEG35
SEG36
SEG37
SEG38
SEG39
SEG4
SEG5
SEG6
SEG7
SEG8
SEG9
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG40
SEG3
SEG2
SEG1
COM8
COM7
COM6
COM5
COM4
COM3
COM2
COM1
IC1-54(P00)
R120 4.7K
IC1-55(P37)
R121 4.7K
IC1-56(P36)
R122 4.7K
IC1-57(P35)
R123 4.7K
IC1-58(P34)
R124 4.7K
IC1-59(P33)
IC1-60(P32)
R126 4.7K
R125 4.7K
IC1-61(P31)
R127 4.7K
IC1-62(P30)
R128 4.7K
R129 4.7K
R130 4.7K
R131 4.7K
IC1-63(P87)
IC1-64(P86)
IC1-65(P85)
IC1-66(P84)
R133 510KR132 33K
IC1-53(P01)
VC
GND
C120 0.1uF/50V
C121
C123
C122
0.1uF/50V
0.1uF/50V
0.1uF/50V
C126
0.1uF/50V
C125
0.1uF/50V
C128
0.1uF/50V
0.1uF/50V
0.1uF/50V
C127
C129
C124
0.1uF/50V
LCD:RLCDSA145DRZZ
1
69
95
19
20
43
44
R134
15K
INT
MAIN
D0
D1
D2
D3
D4
D5
D6
D7
SUB
RESET
GND
VC
(1)
(30)
IC3
SEG20
SEG19
SEG18
SEG17
SEG16
SEG15
SEG14
SEG13
SEG12
SEG7
SEG6
SEG5
SEG4
SEG3
SEG2
SEG1
SEG0
SEG24
SEG23
SEG22
SEG21
SEG28
SEG27
SEG26
SEG25
SEG29
SEG33
SEG32
SEG31
SEG30
SEG34
SEG14
SEG13
SEG12
SEG11
SEG10
SEG9
SEG8
SEG7
SEG6
SEG22
SEG21
SEG20
SEG19
SEG18
SEG17
SEG16
SEG15
SEG27
SEG28
SEG29
SEG30
SEG31
SEG32
SEG33
SEG34
SEG35
SEG36
SEG37
SEG38
SEG39
SEG40
(56)
(31)
70
MAIN1
MAIN2
: IF NOT SPECIFIED 1/10W ±5%
: IF NOT SPECIFIED 1SS355
: IF NOT SPECIFIED 0.01 uF/25V or 50V
NOTE :
Page 44
R939(W)
14 – 9
[6] Jog and Switch Unit Circuit
Figure S-5. Jog and Switch Unit Circuit
: IF NOT SPECIFIED 0.01uF / 25V or 50V : IF NOT SPECIFIED 1/10W ±5%
R68 15K
R69 15K
R70 15K
15K
R73
R72
C60
C61
C62
C63
R72 -- R75 C60 -- C63
R71
R75
R74
J-6 J-5 J-2 J-1
J-3J-4J-8 J-7J-12 J-9J-11 J-10J-13
IC1-6(P73)
VC
IC1-9(P70)
IC1-8(P71)
IC1-7(P72)
VR1
RSW1
GND
R52
R53
R54
15K
4.7K
4.7K
C50C51
C52
100K
100K
R50
R51
IC1-77(AN4)
IC1-18(P47)
IC1-22(INT1)
CN-J
B13B-PH-K-S
A
B
3
1
2
C
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
SW9
SW10
SW13
SW12
SW11
SWITCH UNIT
100K x4
330pF/50V x4
Page 45
R939(W)
14 – 10
[7] Printed Wiring Board
Figure S-6. Printed Wiring Board of Power Unit
DIP
1
1
3
5
1
Q1
B
R3
(J1)
(J2)
E
R4
R2
R6
D1
B
E
Q2
ROTI
MICRO
OL:TTM TH CH:BH
8
ZD2
RY9
RY2
DAMP
CF
FM
RY1
91
17
RY3 RY4
1
4
CN-B
CN-C
CN-E
CN-A
CN-D
1
15 1 4
WH2
C5
Q3
D2
B
E
WH1
2
R5
3
D7
D6
D8
RY8
RY7
POWER CONT
RY6
RY5
D4
D5
4 5
6
C3
C4
C2
D10
VRS1
C1
R1
ZD1
7
SP1
D9
D3
Page 46
R939(W)
14 – 11
MEMO
[8] Printed Wiring of Board of Switch Unit
Figure S-7. Printed Wiring of Board of Switch Unit
Page 47
PARTS LIST
HOW TO ORDER REPLACEMENT PARTS
To have your order filled promptly and correctly, please furnish the following information.
1. MODEL NUMBER
2. REF. NO.
3. PART NO.
4. DESCRIPTION
MICROWAVE OVEN WITH
GRILL AND CONVECTION
MODELS
R-939 R-939
R939(W)
(BK) (IN)
PartsGuide
[1] OVEN PARTS
PACKING AND ACCESSORIES
LOW RACK
HIGH RACK
INTO THE OVEN CAVITY
Parts marked "*" may cause undue microwave exposure. Parts marked " " are used in voltage more than 250V.
CONTENTS
DOOR PROTECTION SHEET
(SPADPA178WRE0)
ROLLER STAY ASSEMBLY
OPERATION MANUAL WITH COOKBOOK
MENU LABEL
TURNTABLE TRAY
R-939
(W)
[2] CONTROL PANEL AND DOOR
PARTS
INDEX
TOP PAD ASSEMBLY
(FPADBA640WRKZ)
PROTECTION SHEET
(SPADPA025URE0)
QUICK START GUIDE
(TINS-A703WRRZ)
CAUTION LABEL
(TCAUHA024URR0)
BOTTOM PAD ASSEMBLY
(FPADBA641WRKZ)
SQUARE TRAY for only R-939(BK)
BAKING TRAY
(PSRA-A001URH0)
SQUARE RACK for only R-939(BK)
(FAMI-A003URK1)
ACCESSORY HOLDER
(SPADPA019URE0)
Not Replaceable Items.
PACKING CASE SPAKCE407WRRZ [R-939(W)] SPAKCE416WRRZ [R-939(IN)] SPAKCE417WRRZ [R-939(BK)]
This document has been published to be used for after sales service only. The contents are subject to change without notice.
Page 48
R939(W)
[1] OVEN PARTS
2-2
7-12
7-8
4-14
7-11
6-2
4-13
7-17
7-16
4-3
4-37
4-15
4-10
6-1
GH
4-40
4-36
7-12
7-16
7-10
4-4
TTM
4-34
4-39
2-4
4-11
7-9
TC2
7-8
7-16
4-31
7-16
7-15
TC1
SW2
SW3
SW1
7-8
7-16
1-5
MG
7-17
7-16
7-4
7-16
7-15
4-30
4-1
7-6
C
7-16
4-24
4-43
4-16
1-1
7-3
7-2
7-3
4-19
4-23
7-11
4-2
4-41
4-1
7-3
CH
4-38
4-26
7-16
7-3
2-1
7-3
4-25
4-22
4-7
4-5
DM
7-10
4-21
7-10
4-20
7-3
7-14
4-17
4-18
4-6
7-5
7-13
OL
SW4
CM
7-8
TC3
4-27
4-28
4-9
7-10
4-12
7-17
1-2
7-16
7-15
2-3
7-16
2-3
7-16
4-29
1-4
4-42
7-16
2
T
7-1
F1
1-3
7-15
4-35
7-16
4-33
7-15
4-32
7-7
FM
7-16
7-16
6-10
Page 49
R939(W)
NO. PARTS CODE
PRICE
RANK
NEW
MARK
PAR T RANK
[1] OVEN PARTS
ELECTRIC PARTS
!
!
*
!
!
CABINET PARTS
OVEN PARTS
* 4-4 DOVN-A024URK0 BU Oven cavity
* 4-31 PHOK-A002URF1 AT Latch hook
MISCELLANEOUS
SCREWS, NUTS AND WASHERS
C RC-QZA219WRE1 AS High voltage capacitor
CH RHET-A269WRZ1 AY Convection heating element
CM RMOTEA415WRZ1 BB Convection motor
DM RMOTDA269WRZ1 AP Damper motor
F1 QFS-BA012WRZZ AG Fuse 20A
FM RMOTEA002URE2 AV Fan motor
GH RHET-A231WRZ1 AU Grill heating element
MG RV-MZA264WRE1 BG Magnetron
OL RLMPTA066WRE1 AP Oven lamp SW1 QSW-MA146WRZ1 AM Monitored latch switch SW2 QSW-MA147WRZ1 AM Stop switch SW3 QSW-MA146WRZ1 AM Monitor switch SW4 QSW-MA147WRZ1 AM Damper switch
T RTRN-A016URE2 BL High voltage transformer TC1 RTHM-A098WRE0 AK Thermal cut-out 125°C (MG) TC2 RTHM-A109WRE0 AM Thermal cut-out 170°C (GRILL) TC3 RTHM-A109WRE0 AM Thermal cut-out 170°C (CONV.)
TTM RMOTDA267WRZ1 AP Turntable motor
1-1 FH-DZA035WRE1 AS High voltage rectifier assembly 1-2 QACCVA004URE3 AT Power supply cord 1-3 FPWBFA309WRE4 AT Noise filter (F2: Fuse F8A) 1-4 RTRN-A529WRE1 AW TC transformer 1-5 FH-HZA075WRE0 AS Thermistor
2-1 GCABDA005URP1 BC Back plate 2-2 GCABUB051WRPZ BM Outer case cabinet [R-939(W)] 2-2 GCABUB052WRPZ BN Outer case cabinet [R-939(BK)] [R-939(IN)] 2-3 GLEGPA057WRE2 AF Foot 2-4 GDAI-A003URP3 BA Base plate
4-1 PCUSUA312WRP0 AC Cushion 4-2 PCUSUA050URE0 AB Cushion 4-3 LANGFA002URP0 AL Cavity support angle
4-5 MCAMPA001URF1 AF Damper cam 4-6 LANGTA009URP2 AG Damper angle 4-7 FFTA-A001URK0 AM Damper assembly
4-9 PDUC-A011URF1 AQ Air intake duct 4-10 PDUC-A014URP0 AH Exhaust duct 4-11 PSKR-A010URP0 AF Partition plate B 4-12 PDUC-A012URP0 AL Air duct 4-13 LANGQA017URP0 AF Grill heater angle 4-14 QTANNA001URP0 AC Earth plate 4-15 PREFHA001URP0 AS Grill reflector 4-16 LANG-A054WRP1 AK Convection heater angle 4-17 LANGQA308WRP1 AK Convection motor angle 4-18 NFANMA003URP0 AF Cooling fan 4-19 PDUC-A042URP0 AG Convection duct 4-20 PPIPFA005UR10 AK Pipe 4-21 PSKR-A013URP0 AG Air separate angle A 4-22 PSKR-A014URP0 AF Air separate angle B 4-23 PSKR-A015URP0 AF Air separate angle C 4-24 PSKR-A016URP0 AF 4-25 PSLDHA005URP0 AQ Rear heat cover 4-26 LANGQA018URP1 AM Convection heater angle A 4-27 PFPF-A002URE1 AL Heat insulating material 4-28 PSKR-A012URP0 AG Air separate angle E 4-29 PSKR-A308WRF1 AL Rear barrier 4-30 NFANMA004URP0 AG Convection fan
4-32 PDUC-A016URF1 AQ Fan duct 4-33 NFANJA038WRE0 AG Fan blade 4-34 GCOVHA002URP0 AG Bottom heater cover 4-35 LANGFA001URP1 AL Chassis support 4-36 NCPL-A040WRE2 AL Coupling 4-37 PCOVPA309WRE0 AF Waveguide cover 4-38 PFPF-A003URE2 AM Heat insulating material 4-39 PFILWA001URP0 AG Lamp filter 4-40 PPACGA101WRE0 AF O-ring 4-41 PSLDHA002URP3 AS Heater cover right 4-42 PSPAGA001WRE0 AB Vibration proof cushion 4-43 LBNDKA111WRP1 AG Capacitor holder
6-1 FROLPA060WRK0 AW Roller stay
6-2 NTNT-A040WRE0 AZ Turntable tray 6-10 LHLDKA008WRF1 AF P-clip
7-1 XHPS740P08K00 AB Screw: 4mm x 8mm
7-2 LX-EZA042WRE0 AB Special screw
7-3 XCBWW30P06000 AA Screw: 3mm x 6mm
7-4 XNEUW40-32000 AA Nut: 4mm x 3.2mm
7-5 XRES740-06000 AB Ring
Air separate angle D
DESCRIPTION
3
Page 50
R939(W)
NO. PARTS CODE
PRICE
RANK
NEW
MARK
PAR T
RANK
[1] OVEN PARTS
7-6 XWSUW40-10000 AA Washer: 4mm x 1.0mm 7-7 XEPS740P25000 AB Screw: 4mm x 25mm 7-8 XHPS730P06000 AB Screw : 3mm x 6mm
7-9 XJPS740P10X00 AB Screw: 4mm x 10mm 7-10 XHPS740P06000 AB Screw: 4mm x 6mm 7-11 XOTWW40P10000 AA Screw : 4mm x 10mm 7-12 XBPWW30P05K00 AA Screw: 3mm x 5mm 7-13 XHTWW40P08000 AC Screw: 4mm x 8mm 7-14 XJBS730P16000 AC Screw:3mm x 16mm 7-15 XHTS740P08RV0 AG Screw: 4mm x 8mm 7-16 LX-CZA001URE0 AC Special screw 7-17 XOTS740P10000 AB Screw: 4mm x 10mm
[2] CONTROL PANEL AND DOOR PARTS
5-2
5-1
5-1-2
5-1-3
5-1-11
5-1-8
5-1-8
5-1-1
5-1-5
3-4
3-6
3-8
DESCRIPTION
3-5
3-13
3-12
3-13
3-1
3-13
3-13
3-13
6-11
5-1-4
5-1-10
6-3
6-12
6-6
6-4
6-14
5-1-7
6-7
6-5
6-13
5-1-6
5-1-9
3-7
3-11
3-10
6-8
3-9
6-9
Actual wire harness may be different than illustration.
3-2
3-3
4
Page 51
R939(W)
NO. PARTS CODE
PRICE
RANK
NEW
MARK
PAR T RANK
[2] CONTROL PANEL AND DOOR PARTS
CONTROL PANEL PARTS
3-1 DPWB-A406DRKZ BR CPU unit 3-2 DPWBFA226URK0 BQ Power unit 3-3 DPWB-A411DRKZ BC Switch unit 3-4 HPNLCC006WRRZ AV Control panel [R-939(W)] 3-4 HPNLCC004WRRZ AV Control panel [R-939(BK)] 3-4 HPNLCC003WRRZ AX Control panel [R-939(IN)] 3-5 GMADIA163WRRZ AL Display window 3-6 JBTN-B367WRFZ AG Key button A [R-939(W)] 3-6 JBTN-B371WRTZ AG Key button A [R-939(BK)] [R-939(IN)] 3-7 JBTN-B368WRRZ AG Key button B [R-939(W)] 3-7 JBTN-B372WRRZ AG Key button B [R-939(BK)] [R-939(IN)] 3-8 JBTN-B369WRRZ AG Key button C [R-939(W)] 3-8 JBTN-B373WRRZ AG Key button C [R-939(BK)] [R-939(IN)] 3-9 JBTN-B370WRFZ AG Clear button [R-939(W)]
3-9 JBTN-B374WRTZ AH Clear button [R-939(BK)] [R-939(IN)] 3-10 JKNBKA766WRFZ AG Timer knob [R-939(W)] 3-10 JKNBKA769WRTZ AG Timer knob [R-939(BK)] [R-939(IN)] 3-11 JKNBKA767WRFZ AG Vari knob [R-939(W)] 3-11 JKNBKA770WRTZ AG Vari knob [R-939(BK)] [R-939(IN)] 3-12 MSPR-A006WREZ AF Switch spring 3-13 XEPS730P10X00 AA Screw : 3mm x 10mm
DOOR PARTS
* 5-1 CDORFB049WRKZ BX Door panel assembly [R-939(W)] * 5-1 CDORFB051WRKZ Door panel assembly [R-939(BK)] * 5-1 CDORFA050WRKZ BV Door panel assembly [R-939(IN)] * 5-1-1 GCOVHA024URF0 AT Choke cover * 5-1-2 DDORFB260WRKZ BF Door panel * 5-1-3 GWAKPB045WRFZ AT Door frame [R-939(W)] * 5-1-3 GWAKPB048WRFZ AT Door frame [R-939(BK)] * 5-1-3 GWAKPA046WRTZ BD Door frame [R-939(IN)]
5-1-4 JHNDPA259WREZ AY Door handle [R-939(W)]
JHNDPA264WREZ BA Door handle [R-939(BK)] [R-939(IN)]
5-1-4
* 5-1-5 LSTPPA017URF0 AK Latch head
5-1-6 MSPRTA197WREZ AF Latch spring 5-1-7 PGLSPA668WREZ AX Front door glass [R-939(W)] 5-1-7 PGLSPA670WREZ BA Front door glass [R-939(BK)] [R-939(IN)] 5-1-8 XEBS730P06000 AC Screw : 3mm x 6mm 5-1-9 JHNDPA260WRFZ AH Handle cover [R-939(W)]
5-1-9 JHNDPA263WRFZ AN Handle cover [R-939(BK)] [R-939(IN)] 5-1-10 JHNDPA261WRFZ AG Handle base [R-939(W)] 5-1-10 JHNDPA262WRFZ AR Handle base [R-939(BK)] [R-939(IN)] 5-1-11 XBTS740P44XS0 AC Screw : 4mm x 44mm
5-2 LSTPPA018URF0 BB Door stopper
MISCELLANEOUS
6-3 PSRA-A025WRP1 AY Baking tray 6-4 FAMI-A001URK1 AT High rack 6-5 FAMI-A002URK1 AT Low rack 6-6 TLABMB127WRRZ AL Menu label 6-7 TCADCA896WRRZ AP Operation Manual with Cook book 6-8 FW-VZA104URE2 BD Main harness
6-9 FW-VZA074URE4 AN Stop switch harness 6-11 TCAUHA024URR0 AE Caution label [R-939(BK)] [R-939(IN)] 6-12 TINS-A703WRRZ AM Quick start guide 6-13 FAMI-A003URK1 AW Square rack [R-939(BK)] 6-14 PSRA-A001URH0 AZ Square tray [R-939(BK)]
DESCRIPTION
5
Page 52
R939(W)
INDEX
PARTS CODE No.
[ C ] CDORFA050WRKZ 2-5-1 BV CDORFB049WRKZ 2-5-1 BX CDORFB051WRKZ 2-5-1
[ D ] DDORFB260WRKZ 2-5-1-2 BF DOVN-A024URK0 1-4-4 BU DPWB-A406DRKZ 2-3-1 BR DPWB-A411DRKZ 2-3-3 BC DPWBFA226URK0 2-3-2 BQ
[ F ] FAMI-A001URK1 2-6-4 AT FAMI-A002URK1 2-6-5 AT FAMI-A003URK1 2-6-13 AW FFTA-A001URK0 1-4-7 AM FH-DZA035WRE1 1-1-1 AS FH-HZA075WRE0 1-1-5 AS FPWBFA309WRE4 1-1-3 AT FROLPA060WRK0 1-6-1 AW FW-VZA074URE4 2-6-9 AN FW-VZA104URE2 2-6-8 BD
[ G ] GCABDA005URP1 1-2-1 BC GCABUB051WRPZ 1-2-2 BM GCABUB052WRPZ 1-2-2 BN GCOVHA002URP0 1-4-34 AG GCOVHA024URF0 2-5-1-1 AT GDAI-A003URP3 1-2-4 BA GLEGPA057WRE2 1-2-3 AF GMADIA163WRRZ 2-3-5 AL GWAKPA046WRTZ 2-5-1-3 BD GWAKPB045WRFZ 2-5-1-3 AT GWAKPB048WRFZ 2-5-1-3 AT
[ H ] HPNLCC003WRRZ 2-3-4 AX HPNLCC004WRRZ 2-3-4 AV HPNLCC006WRRZ 2-3-4 AV
[ J ] JBTN-B367WRFZ 2-3-6 AG JBTN-B368WRRZ 2-3-7 AG JBTN-B369WRRZ 2-3-8 AG JBTN-B370WRFZ 2-3-9 AG JBTN-B371WRTZ 2-3-6 AG JBTN-B372WRRZ 2-3-7 AG JBTN-B373WRRZ 2-3-8 AG JBTN-B374WRTZ 2-3-9 AH JHNDPA259WREZ 2-5-1-4 AY JHNDPA260WRFZ 2-5-1-9 AH JHNDPA261WRFZ 2-5-1-10 AG JHNDPA262WRFZ 2-5-1-10 AR JHNDPA263WRFZ 2-5-1-9 AN JHNDPA264WREZ 2-5-1-4 BA JKNBKA766WRFZ 2-3-10 AG JKNBKA767WRFZ 2-3-11 AG JKNBKA769WRTZ 2-3-10 AG JKNBKA770WRTZ 2-3-11 AG
[ L ] LANG-A054WRP1 1-4-16 AK LANGFA001URP1 1-4-35 AL LANGFA002URP0 1-4-3 AL LANGQA017URP0 1-4-13 AF LANGQA018URP1 1-4-26 AM LANGQA308WRP1 1-4-17 AK LANGTA009URP2 1-4-6 AG LBNDKA111WRP1 1-4-43 AG LHLDKA008WRF1 1-6-10 AF LSTPPA017URF0 2-5-1-5 AK LSTPPA018URF0 2-5-2 BB LX-CZA001URE0 1-7-16 AC LX-EZA042WRE0 1-7-2 AB
[ M ] MCAMPA001URF1 1-4-5 AF MSPR-A006WREZ 2-3-12 AF MSPRTA197WREZ 2-5-1-6 AF
[ N ] NCPL-A040WRE2 1-4-36 AL NFANJA038WRE0 1-4-33 AG NFANMA003URP0 1-4-18 AF NFANMA004URP0 1-4-30 AG
PRICE RANK
NEW
MARK
PAR T
RANK
PARTS CODE No.
NTNT-A040WRE0 1-6-2 AZ
[ P ] PCOVPA309WRE0 1-4-37 AF PCUSUA050URE0 1-4-2 AB PCUSUA312WRP0 1-4-1 AC PDUC-A011URF1 1-4-9 AQ PDUC-A012URP0 1-4-12 AL PDUC-A014URP0 1-4-10 AH PDUC-A016URF1 1-4-32 AQ PDUC-A042URP0 1-4-19 AG PFILWA001URP0 1-4-39 AG PFPF-A002URE1 1-4-27 AL PFPF-A003URE2 1-4-38 AM PGLSPA668WREZ 2-5-1-7 AX PGLSPA670WREZ 2-5-1-7 BA PHOK-A002URF1 1-4-31 AT PPACGA101WRE0 1-4-40 AF PPIPFA005UR10 1-4-20 AK PREFHA001URP0 1-4-15 AS PSKR-A010URP0 1-4-11 AF PSKR-A012URP0 1-4-28 AG PSKR-A013URP0 1-4-21 AG PSKR-A014URP0 1-4-22 AF PSKR-A015URP0 1-4-23 AF PSKR-A016URP0 1-4-24 AF PSKR-A308WRF1 1-4-29 AL PSLDHA002URP3 1-4-41 AS PSLDHA005URP0 1-4-25 AQ PSPAGA001WRE0 1-4-42 AB PSRA-A001URH0 2-6-14 AZ PSRA-A025WRP1 2-6-3 AY
[ Q ] QACCVA004URE3 1-1-2 AT QFS-BA012WRZZ 1-F1 AG QSW-MA146WRZ1 1-SW1 AM
" 1-SW3 AM
QSW-MA147WRZ1 1-SW2 AM
" 1-SW4 AM
QTANNA001URP0 1-4-14 AC
[ R ] RC-QZA219WRE1 1-C AS RHET-A231WRZ1 1-GH AU RHET-A269WRZ1 1-CH AY RLMPTA066WRE1 1-OL AP RMOTDA267WRZ1 1-TTM AP RMOTDA269WRZ1 1-DM AP RMOTEA002URE2 1-FM AV RMOTEA415WRZ1 1-CM BB RTHM-A098WRE0 1-TC1 AK RTHM-A109WRE0 1-TC2 AM
" 1-TC3 AM RTRN-A016URE2 1-T BL RTRN-A529WRE1 1-1-4 AW RV-MZA264WRE1 1-MG BG
[ T ] TCADCA896WRRZ 2-6-7 AP TCAUHA024URR0 2-6-11 AE TINS-A703WRRZ 2-6-12 AM TLABMB127WRRZ 2-6-6 AL
[ X ] XBPWW30P05K00 1-7-12 AA XBTS740P44XS0 2-5-1-11 AC XCBWW30P06000 1-7-3 AA XEBS730P06000 2-5-1-8 AC XEPS730P10X00 2-3-13 AA XEPS740P25000 1-7-7 AB XHPS730P06000 1-7-8 AB XHPS740P06000 1-7-10 AB XHPS740P08K00 1-7-1 AB XHTS740P08RV0 1-7-15 AG XHTWW40P08000 1-7-13 AC XJBS730P16000 1-7-14 AC XJPS740P10X00 1-7-9 AB XNEUW40-32000 1-7-4 AA XOTS740P10000 1-7-17 AB XOTWW40P10000 1-7-11 AA XRES740-06000 1-7-5 AB XWSUW40-10000 1-7-6 AA
PRICE
RANK
NEW
MARK
PART
RANK
6
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