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R- 308JK
R - 308JS
R-308JW
R-309JW

20

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 all 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.

TOUCH CONTROL PANEL SERVICING

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, 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 activates 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
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 activates 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: 30W

(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 connectors 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.

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
MICROWAVE 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.

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.

approx. 1M ohm

Pin No.

Signal

I/O

Description

63

BZO90

OUT

Signal to sound buzzer (2.0 kHz).

A: key touch sound.

B: Completion sound.

64

P20

OUT

Terminal not used.

A

B

0.1 sec.

2.0 sec.

H : GND

L : -5V

H : GND

L : -5V

Summary of Contents for R-308JK

Page 1: ...D BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY INSIDE FRONT COVER BEFORE SERVICING INSIDE FRONT COVER WARNING TO SERVICE PERSONNEL 1 MICROWAVE MEASUREMENT PROCEDURE 2 FOREWORD AND WARNING 3 PRODUCT SPECIFICATIONS 4 GENERAL INFORMATION 4 OPERATION 6 TROUBLESHOOTING GUIDE 9 TEST PROCEDURE 10 TOUCH CONTROL PANEL 17 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE...

Page 2: ...eration and transmission systems shall be repaired replaced or adjusted by procedures described in this manual before the oven is released to the owner e A microwave leakage check to verify compliance with the Federal Performance Standard should be performed on each oven prior to release to the owner BEFORE SERVICING Before servicing an operative unit perform a microwave emission check as per the ...

Page 3: ...voltage capacitor 4 Disconnect the leads to the primary of the power transformer 5 Ensure that the leads remain isolated from other components and oven chassis by using insulation tape 6 After that procedure reconnect the power supply cord When the testing is completed 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block it open 3 Discharge high voltage capacitor...

Page 4: ...ven cavity The water container shall be a low form of 600 ml 20 oz beaker with an inside diameter of approx 8 5 cm 3 1 2 in and made of an electrically nonconductive 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 Set the cooking control on Full Power Cooking Mode ...

Page 5: ...tive C The door packing is not damaged D The door is not deformed or warped E There is no other visible damage with the oven Servicing and repair work must be carried out only by trained service personnel DANGER Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing Service person nel Do not contact the following parts while the appliance ...

Page 6: ...1 Subchapter J SPECIFICATION GENERAL INFORMATION GROUNDING INSTRUCTIONS This oven is equipped with a three prong grounding plug It must be plugged into a wall receptacle that is properly installed and grounded in accordance with the National Electrical Code and local codes and ordinances In the event of an electrical short circuit grounding reduces the risk of electric shock by providing an escape...

Page 7: ...e support Carefully place the turntable support in the center of the oven floor 8 Removable turntable Place the turntable on the turntable support securely The turntable will rotate clockwise or counterclockwise Only remove for cleaning 9 Ventilation openings Rear 10 Oven light It will light when oven is operating or when the door is open 11 Waveguide cover DO NOT REMOVE 12 Auto Touch control pane...

Page 8: ... energized the oven lamp remains on and the digital read out displays the time still remaining in the cook cycle when the door was opened 7 The monitor switch electrically monitors the operation of the secondary interlock switch and primary interlock relay and is mechanically associated with the door so that it will function in the following sequence 1 When the door opens from the closed position ...

Page 9: ...V 120V AC 60 Hz OVEN LAMP OVEN LAMP RELAY TURN TABLE MOTOR FAN MOTOR POWER TRANSFORMER MONITOR SWITCH RECTIFIER MAGNETRON SECONDARY INTERLOCK SWITCH TTM OL FM C T FUSE OR N O N O COM COM DOOR SENSING SWITCH RY1 RY2 CONTROL UNIT PRIMARY INTERLOCK RELAY GRN B2 CAPACITOR 0 94µF AC 2200V B1 120V AC 60 Hz OVEN LAMP OVEN LAMP RELAY TURN TABLE MOTOR FAN MOTOR POWER TRANSFORMER MONITOR SWITCH RECTIFIER MA...

Page 10: ...ARE REPLACED AS AN ASSEMBLY TURNTABLE MOTOR The turntable motor rotates the turntable located on the bottom of the oven cavity so that the food on the turntable is cooked evenly The turntable may turn in either direction COOLING FAN MOTOR The cooling fan motor drives a blade which draws external cool air This cool air is directed through the air vents surrounding the magnetron and cools the magnet...

Page 11: ... part FFS BA034WRKZ as an assembly IMPORTANT Whenever troubleshooting is performed with the power supply cord disconnected It may in some cases be necessary to connect the power supply cord after the outer case has been removed in this event 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 t...

Page 12: ...nto DEFROST but food is not defrosted well OFF CONDITION PROBLEM CONDITION SHORT IN POWER CORD SHORT OR OPENED WIRING MAGNETRON POWER TRANSFORMER H V RECTIFIER ASSEMBLY HIGH VOLTAGE CAPACITOR TEMPERATURE FUSE OR THERMAL CUT OUT OVEN PRIMARY INTERLOCK SYSTEM SECONDARY INTERLOCK SWITCH MONITOR SWITCH C T FUSE OVEN LAMP COOLING FAN MOTOR TURNTABLE MOTOR TOUCH CONTROL PANEL WRONG OPERATION LOW VOLTAGE...

Page 13: ...d an accurate mercury thermometer or thermocouple type temperature tester For accurate results the following procedure must be followed carefully 1 Fill the measuring cup with 16 oz 453cc of tap water and measure the temperature of the water with a thermometer or thermocouple temperature tester Stir the thermometer or thermocouple through the water until the temperature stabilizes Record the tempe...

Page 14: ...ischarge high voltage capacitor 4 A continuity check across the temperature fuse terminals should indicate a closed circuit unless the temperature of the temperature fuse reaches approximately 302 F 150 C An open temperature fuse indicates overheating of the oven exchange the temperature fuse and check inside of oven cavity and for improper setting of cooking time or operation of control unit Chec...

Page 15: ...e state of the relay contacts using a ohmmeter The relay contacts should be open If the relay contacts are closed replace the circuit board entirely or the relay itself 5 Reconnect all leads removed from components during testing 6 Reinstall the outer case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 Run the oven and check all functions G MONITOR SWITCH TEST 1 Disc...

Page 16: ...and ohmmeter In this service manual the touch control panel assembly is divided into two units Control Unit and Key Unit and also the Control Unit is divided into two units CPU Unit and Power Unit and troubleshooting by unit replacement is described according to the symptoms indicated Before testing 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block it open 3 D...

Page 17: ...t circuit When the pad is released the ohmmeter should indicate open circuit If incorrect readings are obtained the key unit is faulty and must be replaced About the other pads the above method may be used 5 Reconnect all leads removed from components during testing 6 Re install the outer case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 Run the oven and check all ...

Page 18: ...60 27sec 30 40sec 6 If improper operation is indicated the control unit is probably defective and should be checked L DEFROST TEST To protect the electronic circuits this model is provided with a fine foil pattern added to the primary on the PWB this foil pattern acts as a fuse 1 Foil pattern check and repairs 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block ...

Page 19: ...cated among them are explained below Key Unit The key unit is composed of a matrix signals generated in the LSI are sent to the key unit through P22 P23 P24 P25 P26 P31 P32 and P33 When a key pad is touched a signal is completed through the key unit and passed back to the LSI through P50 P51 P52 and P53 to perform the function that was requested Control Unit Control unit consists of LSI reset circ...

Page 20: ...lation frequency input setting The internal clock frequency is set by inserting the resistor capacitor oscillation circuit with respect to X2 terminal 11 X2 OUT Internal clock oscillation frequency control output Output to control oscillation input of X1 12 RESET IN Auto clear terminal Signal is input to reset the LSI to the initial state when power is applied 13 15 P00 P02 OUT Terminal not used 1...

Page 21: ...s input to P50 P51 P52 and P53 terminal while one of G1 line keys on key matrix is touched 55 P32 OUT Key strobe signal Signal applied to touch key section A pulse signal is input to P50 P51 P52 and P53 terminal while one of G2 line keys on key matrix is touched 56 P31 OUT Key strobe signal Signal applied to touch key section A pulse signal is input to P50 P51 P52 and P53 terminal while one of G3 ...

Page 22: ... 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 30W 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 ...

Page 23: ...ts more often when using lead free solder To reduce bit wear care should be taken to clean the bit thoroughly after each use Sn Ag Cu 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 Power Transformer Magnetron High Voltage Rectifier Assembly High Volta...

Page 24: ... High voltage capacitor and High voltage rectifier assembly 2 Hot parts Oven lamp Magnetron Power transformer and Oven cavity WARNING FOR WIRING 3 Sharp edge Bottom plate Oven cavity Waveguide flange and other metallic plate 4 Movable parts to prevent a fault Fan blade Fan motor Turntable motor Switch Switch lever Open button 3 Do not catch the wire leads in the outer case cabinet 4 Insert the pos...

Page 25: ...ASKET IS IN PLACE AND MOUNT ING SCREWS ARE TIGHTENED SECURELY 7 Remove the one 1 screw holding capacitor holder to bottom plate 8 Remove one 1 screw holding high voltage rectifier assembly to capacitor holder 9 Disconnect rectifier terminal from capacitor High voltage rectifier assembly is now free 10 Remove capacitor holder Capacitor is now free CAUTION WHEN REPLACING HIGH VOLTAGE RECTI FIER AND ...

Page 26: ... LED sheet LCD holder Screws Rubber connector Figure C 2a Graphic Sheet and Membrane Switch Replacement Slit Ribbon cable of membrane switch Control panel frame Figure C 2b Rebbon Cable of Membrane Switch 1 Disconnect the power supply cord 2 Remove turntable and turntable support from oven cavity 3 Lay the oven on it s backside Remove the turntable motor cover by snipping off the material in four ...

Page 27: ... of the monitor circuit Refer to chapter Test Procedure and Adjustment procedure 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 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block it open 3 Discharge high voltage capacitor If the door sensing switc...

Page 28: ...4 Put sealer film on door panel Refer to Sealer Film about how to handle new one 5 Catch two 2 pins of door panel on two 2 hole of upper and lower oven hinges 6 Reinstall choke cover to door panel by pushing Note After any service to the door A Make sure that door sensing switch and secondary interlock switch are operating properly Refer to chapter Test Procedures B An approved microwave survey me...

Page 29: ...M NO NOTE The neutral WHT wire must be connected to the terminal with N mark on the power supply cord GRY W H T WHT GRY RED GRY GRY R E D P N K B L K R E D GRN GRY GRY GRN BLK GRY WHT GRY RED RED BLK PNK GRY C T FUSE FAN MOTOR TEMPERATURE FUSE OVEN BLK WHT 2 1 WHT WHT WHT WHT RED RY1 PRIMARY INTERLOCK RELAY CN B CN B T1 1 2 N O COM RY2 N O COM CONTROL UNIT H N NOTE The grounding conductor of the p...

Page 30: ... D1 D2 D1 D4 1N4002 X 4 SEG1 SEG3 SEG2 SEG4 SEG5 SEG6 SEG7 SEG8 SEG9 SEG10 SEG11 SEG12 COM3 COM2 COM1 B1 DOOR RST 5V INT BZ COM M C40 GND R1 560 1 2W CN B AC H AC N AC120V 60HZ G6 G7 G8 G3 J1 DTA123JS G10 G11 G12 G4 G5 G9 VR R30 3 3K 0 01uF 25V COM1 COM2 COM3 SEG1 SEG2 SEG3 SEG4 SEG5 SEG6 P71 P72 AVDD P01 P00 RE SET X2 X1 VSS VDD XT2 XT1 IC P53 P52 P51 P50 P02 BL 17 G2 G1 SEG13 SEG14 R60 R61 R7 R8...

Page 31: ...R 308JK R 308JS R 308JW R 309JW 29 Figure S 3 Printed Wiring Board of Power Unit 6 4 5 1 2 3 6 4 5 1 2 3 A B C D E F G H A B C D E F G H ...

Page 32: ...angeable for production use 1 1 11 RV MZA288WRE0 Magnetron 1 BK 1 11 RV MZA321WRZZ Magnetron Interchangeable 1 BH CABINET PARTS 2 1 GCABUA889WRPZ Outer case cabinet R 308JK 1 BF 2 1 GCABUA883WRPZ Outer case cabinet R 308JW R 309JW 1 BF 2 1 GCABUA866WRPZ Outer case cabinet R 308JS 1 BF 2 2 GDAI A360WRWZ Bottom plate 1 AS 2 3 GLEGPA074WRE0 Foot 4 AC CONTROL PANEL PARTS 3 1 DPWBFC414WRUZ Control unit...

Page 33: ...JS 1 AX 5 4 HPNL A823WRRZ Door screen R 308JK R 308JS 1 AS 5 4 HPNL A825WRRZ Door screen R 308JW 1 AS 5 4 HPNL A826WRRZ Door screen R 309JW 1 AS 5 5 LSTPPA188WRF0 Latch head R 308JK R 308JS 1 AG 5 5 LSTPPA230WRFZ Latch head R 308JW R 309JW 1 AG 5 6 MSPRTA187WRE0 Spring 1 AC 5 7 GCOVHA450WRFZ Choke cover R 308JK R 308JS 1 AG 5 7 GCOVHA472WRFZ Choke cover R 308JW R 309JW 1 AL MISCELLANEOUS 6 1 FROLP...

Page 34: ...RTS A A 7 10 4 12 7 1 4 1 4 5 4 4 4 13 6 5 7 3 4 3 4 9 4 12 2 1 1 7 7 3 1 10 1 9 4 10 7 10 7 10 7 8 4 11 7 5 4 17 7 4 7 10 1 5 1 4 4 2 1 1 1 1 1 11 7 7 7 10 7 10 7 7 6 4 7 11 7 12 7 2 7 2 7 10 7 10 7 10 7 6 1 2 7 8 4 8 1 8 7 10 7 8 1 2 2 3 2 2 4 12 4 6 4 14 7 9 1 3 4 16 4 15 1 6 7 1 6 1 6 2 4 7 2 3 2 3 4 12 2 3 ...

Page 35: ...4 5 1 2 3 6 4 5 1 2 3 A B C D E F G H A B C D E F G H 3 2 3 3 3 6 3 8 3 9 3 2 2 3 2 3 3 5 3 4 3 1 3 7 Actual wire harness may be different from illustration 6 3 5 1 5 3 3 2 1 5 2 5 4 5 5 5 7 5 6 DOOR PARTS CONTROL PANEL PARTS MISCELLANEOUS ...

Page 36: ... only for R 308JK FOAM SHEET SPAKHA012WREZ only for R 308JK PLASTIC SHEET for R 308JK SPADPA616WREZ INTO THE OVEN CAVITY TRAY PAD ASSY CPADBA317WRKZ 6 6 INSTRUCTION BOOK 6 2 TURNTABLE TRAY 6 1 TURNRTABLE SUPPORT COPYRIGHT 2004 BY SHARP CORPORATION ALL RIGHTS RESERVED No part of this publication may be reproduced stored in retrieval systems or transmitted in any form or by any means electronic mech...

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