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PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE EXPO-
SURE TO EXCESSIVE MICROWAVE ENERGY

BEFORE SERVICING

CHAPTER 1. WARNING TO SERVICE PERSONNEL

CHAPTER 2. MICROWAVE MEASUREMENT PRO-
CEDURE

CHAPTER 3. FOREWORD AND WARNING

CHAPTER 4. PRODUCT DESCRIPTION

CHAPTER 5. GENERAL INFORMATION

CHAPTER 6. OPERATION

CHAPTER 7. TROUBLESHOOTING GUIDE 

CHAPTER 8. TEST PROCEDURES

CHAPTER 9. TOUCH CONTROL PANEL ASSEMBLY

CHAPTER 10. PRECAUTIONS FOR USING LEAD-
FREE SOLDER

CHAPTER 11. COMPONENT REPLACEMENT AND 
ADJUSTMENT PROCEDURE

CHAPTER 12. CIRCUIT DIAGRAMS

Parts Guide

No. S2504R308KPKW

MICROEAVE OVEN

R-308KK
R-308KW

SERVICE MANUAL

R-308KK

R308KW

MODELS

CONTENTS

SHARP CORPORATION

This document has been published to be used
for after sales service only.
The contents are subject to change without notice.

In the interest of user-safety the oven should be restored to its origi-
nal condition and only parts identical to those specified should be
used.

WARNING TO SERVICE PERSONNEL: Microwave ovens con-
tain circuitry capable of producing very high voltage and cur-
rent, contact with following parts may result in a severe,
possibly fatal, electrical shock. (High Voltage Capacitor, High
Voltage Power Transformer, Magnetron, High Voltage Rectifier
Assembly,  High Voltage Harness etc..)

Summary of Contents for R-308KK

Page 1: ...ER 12 CIRCUIT DIAGRAMS Parts Guide No S2504R308KPKW MICROEAVE OVEN R 308KK R 308KW SERVICE MANUAL R 308KK R308KW MODELS CONTENTS SHARP CORPORATION This document has been published to be used for after sales service only The contents are subject to change without notice In the interest of user safety the oven should be restored to its origi nal condition and only parts identical to those specified ...

Page 2: ...MINITOR FUSE TEST 8 4 11 Procedure I NOISE FILTER TEST 8 4 12 Procedure J TOUCH CONTROL PANEL ASSEMBLY TEST 8 4 13 Procedure K KEY UNIT TEST 8 5 14 Procedure L RELAY TEST 8 6 15 Procedure M DEFROST TEST 8 6 16 Procedure N FOIL PATTERN ON THE PRINTED WIRING BOARD TEST 8 7 CHAPTER 9 TOUCH CONTROL PANEL ASSEM BLY 1 OUTLINE OF TOUCH CONTROL PANEL 9 1 2 DESCRIPTION OF LSI 9 1 3 SERVICING FOR TOUCH CONT...

Page 3: ...components in the interlock monitor door seal and microwave generation 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 a...

Page 4: ...h voltage capacitor 4 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 2 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 cap...

Page 5: ...he oven 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 M...

Page 6: ...rackets 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 personnel 3 DANGER Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing Service personnel Do not contact th...

Page 7: ...for holding food is less Control Complement Touch Control System Clock 1 00 12 59 Timer 0 99 minutes 99 seconds Microwave Power for Variable Cooking Repetition Rate P HI Full power throughout the cooking time P 90 approx 90 of FULL Power P 80 approx 80 of FULL Power P 70 approx 70 of FULL Power P 60 approx 60 of FULL Power P 50 approx 50 of FULL Power P 40 approx 30 of FULL Power P 30 approx 40 of...

Page 8: ...have it replaced with a properly grounded three pronged wall receptacle or have a grounding adapter properly grounded and polarized If the extension cord must be used it should be a 3 wire 15 amp or higher rated cord Do not drape over a countertop or table where it can be pulled on by children or tripped over accidentally CAUTION DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRO...

Page 9: ...NEL NOTE Some one touch cooking features such as MINUTE PLUS are disabled after three minutes when the oven is not in use These fea tures are automatically enabled when the door is opened and closed or the STOP CLEAR pad is pressed ...

Page 10: ...time still remaining in the cook cycle when the door was opened 7 The monitor switch electrically monitors the operation of the sec ondary interlock switch and primary interlock relay and is mechani cally associated with the door so that it will function in the following sequence a When the door opens from the closed position the primary interlock relay RY2 and secondary interlock switch open thei...

Page 11: ...ERLOCK RELAY GRN B2 CAPACITOR 0 19μF AC 2100V B1 FUSE 20A NOISE SUPPRESSION COIL LINE CROSS CAPACITOR 0 22μF AC 250V LINE BYPASS CAPACITOR 0 0033μF AC 125V LINE BYPASS CAPACITOR 0 0033μF AC 125V L N NOISE FILTER MAGNETRON NOTE indicates components with potentials above 250V 120V AC 60 Hz OVEN LAMP OVEN LAMP RELAY TURN TABLE MOTOR FAN MOTOR POWER TRANSFORMER MONITOR SWITCH RECTIFIER MAGNETRON SECON...

Page 12: ...R SENSING SWITCH PRIMARY INTERLOCK RELAY RY2 SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPERATION REFER TO CHAPTER TEST PROCEDURE NOTE MONITOR FUSE AND MONITOR SWITCH ARE REPLACED AS AN ASSEMBLY 4 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 direct...

Page 13: ...r transformer 5 Reinstall the outer case cabinet 6 Reconnect the power supply cord after the outer case is installed 7 Run the oven and check all functions 1 TROUBLESHOOTING CHART RE CK A B C D E F F G H RE RE CK J CK CK CK K L N I POSSIBLE CASE AND DEFECTIVE PARTS SHORT IN POWER CORD SHORT OR OPENED WIRING MAGNETRON POWER TRANSFORMER H V RECTIFIER ASSEMBLY HIGH VOLTAGE CAPACITOR TEMPERATURE FUSE ...

Page 14: ...e to stir the thermometer or thermocouple through the water until the maximum temperature is recorded 4 Subtract the cold water temperature from the hot water temperature The normal result should be32 1 to 59 7 F 17 9 to 33 2 C rise in tempera ture If the water temperatures are accurately measured and tested for the required time period the test results will indicate if the magnetron tube has low ...

Page 15: ...netron especially the cooling fan and air guide 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 CAUTION IF THE TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE REPLACE IT 6 Procedure E THERMAL CUT OUT OVEN TEST 1 Disconnect the pow...

Page 16: ...cts 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 9 Procedure G MONITOR SWITCH TEST 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block it op...

Page 17: ...ting 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 12 Procedure J TOUCH CONTROL PANEL ASSEMBLY TEST The touch control panel consists of circuits including semiconductors such as LSI ICs etc Therefore unlike conventional microwave ovens proper maintenance cannot be performed with only a voltmeter and ohm...

Page 18: ...nnect the power supply cord after the outer case is installed 8 Run the oven and check all functions 4 When 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 4 Reconnect all leads removed from components during testing 5 Re install the outer case cabinet 6 Reconnect the power supply cord after the...

Page 19: ... 10 Discharge high voltage capacitor 11 Reconnect all leads removed from components during testing 12 Re install the outer case cabinet 13 Reconnect the power supply cord after the outer case is installed 14 Run the oven and check all functions 15 Procedure M DEFROST TEST WARNING The oven should be fully assembled before following procedure 1 Place one cup of water in the center of the turntable t...

Page 20: ... 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 7 Follow the troubleshooting guide given below for repair 8 Disconnect th...

Page 21: ...ecause it works on commercial frequency 7 Door Sensing Switch A switch to tell the LSI if the door is open or closed 8 Back Light Circuit A circuit to drive the back light Light emitting diodes LD1 LD3 2 DESCRIPTION OF LSI The I O signal of the LSI are detailed in the following table Symbol Voltage Application VSS 5V LSI IC1 Pin No Signal I O Description 1 P50 IN Signal coming from touch key When ...

Page 22: ...SS IN A D converter power source voltage The power source voltage to drive the A D converter in the LSI 52 P11 IN To input signal which communicates the door open close information to LSI Door close H level signal 0V Door open L level signal 5V 53 P10 OUT Terminal not used 54 P33 OUT Key strobe signal Signal applied to touch key section A pulse signal is input to P50 P51 P52 and P53 terminal while...

Page 23: ...g it connected to the oven b On some models the power supply cord between the touch control panel and the oven proper is so 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 ...

Page 24: ...s 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...

Page 25: ...t 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...

Page 26: ...r to PICTORIAL DIAGRAM 4 Reinstall outer case and check that oven is operating properly 4 HIGH VOLTAGE COMPONENTS REMOVAL HIGH VOLTAGE CAPACITOR AND HIGH VOLT AGE RECTIFIER ASSEMBLY To remove the components proceed as follows 1 Disconnect the power supply cord and remove outer case 2 Open the oven door and block it open 3 Discharge high voltage capacitor 4 Disconnect the high voltage wire of the p...

Page 27: ...rom the control panel frame 7 Tear away the graphic sheet from the control panel frame 8 Tear away the membrane switch from the control panel frame 2 REINSTALLATION 1 Remove remaining adhesive on the control panel frame surfaces with a soft cloth soaked in alcohol 2 Tear the backing paper from the new membrane switch 3 Insert the ribbon cable of the membrane switch into the slit of the control pan...

Page 28: ...haven by pliers and metal pieces may be produced Do not touch the pliers to the coil of the fan motor because the coil may be cut or injured Do not disfigure the bracket by touching with the pli ers 8 Remove the fan blade assembly from the shaft of the fan motor by pulling and rotating the fan blade with your hand 9 Now the fan blade will be free CAUTION Do not re use the removed fan blade because...

Page 29: ...TOR SWITCH REMOVAL 1 REMOVAL 1 Disconnect the power supply cord and remove outer case 2 Open the door and block it open 3 Discharge high voltage capacitor 4 Disconnect wire leads from the switches 5 Remove two 2 screws holding latch hook to oven flange 6 Remove latch hook assembly from oven flange 7 Push outward on the two 2 retaining tabs holding switch in place 8 Switch is now free At this time ...

Page 30: ...Procedure Figure C 4 Latch Switch Adjustments 14 DOOR REPLACEMENT 1 REMOVAL 1 Disconnect the power supply cord 2 Open the door slightly 3 Insert a putty knife thickness of about 0 5mm into the gap between the choke cover and door frame as shown in Figure C 5 to free engaging parts 4 Pry the choke cover by inserting a putty knife as shown Figure C 5 5 Release choke cover from door panel 6 Now choke...

Page 31: ...f microwave energy from oven cavity during cook cycle This function does not require that door be air tight moisture conden sation tight or light tight Therefore occasional appear ance 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 6 Door Replacement 4 SEALER FILM 1 ...

Page 32: ...ANSFORMER COM NO GRY W H T WHT GRY RED GRY GRY R E D P N K B L K W H T R E D GRN GRY GRY GRN BLK GRY WHT GRY RED RED GRN BLK PNK GRY FUSE NOISE FILTER FAN MOTOR TEMPERATURE FUSE OVEN TEMPERATURE FUSE MAGNETRON BLK WHT 2 1 WHT WHT WHT RED RY1 PRIMARY INTERLOCK RELAY CN B CN B T1 1 2 N O COM RY2 N O COM CONTROL UNIT GRY OVEN LAMP PNK RED RED PNK RED WHT Power Supply Cord Screw Oven Cavity Back Plate...

Page 33: ... G 7 SE G 8 SE G 9 SEG 10 SEG 11 SEG 12 COM3 COM2 COM1 B 1 DOOR R S T 5V INT B Z C OM M C 40 G ND R 1 560 1 2W C N B AC H AC N AC 120V 60HZ G 6 G 7 G 8 G 3 J 1 DT A123J S G 10 G 11 G 12 G 4 G 5 G 9 V R R 30 3 3K 0 01uF 25V C OM1 C OM2 C OM3 S E G 1 S E G 2 S E G 3 S E G 4 S E G 5 S E G 6 P 71 P 72 AV DD P 01 P 00 R E S E T X2 X1 V S S V DD XT 2 XT 1 IC P 53 P 52 P 51 P 50 P 02 B L 17 G 2 G 1 SEG 1...

Page 34: ...R308KW 12 3 3 Printed Wiring Board of Power Unit Figure S 3 Figure S 3 Printed Wiring Board of Power Unit ...

Page 35: ...hout notice R308KW R 308KK R 308KW 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 PACKING AND ACCESSORIES Parts marked may cause undue microwave exposure Parts marked are used in voltage more than 250V 1 OVEN PARTS 2 DOOR AND CONTROL PANEL PARTS INDEX ...

Page 36: ...4 12 2 1 7 1 1 13 1 2 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 9 7 2 7 2 7 10 7 10 7 10 7 6 1 12 7 8 4 8 1 8 7 10 7 8 1 2 2 3 2 2 4 12 4 6 4 14 7 1 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 37: ... 11 RV MZA321WRZZ BH Magnetron Interchangeable 1 11 RV MZA340WRZZ Magnetron Interchangeable for production use 1 12 QFS TA014WRE0 AG Temperature fuse 150deg C Magnetron 1 13 FPWBFA385WRKZ AV Noise filter assembly CABINET PARTS 2 1 GCABUA889WRPZ BF Outer case cabinet R 308KK 2 1 GCABUA883WRPZ BF Outer case cabinet R 308KW 2 2 GDAI A360WRWZ AS Bottom plate 2 3 GLEGPA074WRE0 AC Foot OVEN PARTS 4 1 PH...

Page 38: ...R308KW 4 2 DOOR AND CONTROL PANEL PARTS 3 2 6 6 3 3 3 6 3 8 3 9 3 2 2 3 2 3 3 5 3 4 3 1 3 7 6 3 5 1 5 3 3 2 1 5 2 5 4 5 5 5 8 5 7 5 6 ...

Page 39: ...Q LED SHEET 3 7 QCNC A019WRZZ AG Rubber connector 3 8 RLCDSA128DRZZ AQ Liquid crystal display 3 9 XEPSD30P08XS0 AA Screw 3mm x 8mm DOOR PARTS 5 1 FDORFA364WRTZ AS Door panel R 308KK 5 1 FDORFA385WRTZ AZ Door panel R 308KW 5 2 PSHEPA382WRE0 AH Sealer film R 308KK 5 2 PSHEPB017WREZ AR Sealer film R 308KW 5 3 GWAKPA990WRRZ AW Door frame R 308KK 5 3 GWAKPA988WRRZ AW Door frame R 308KW 5 4 HPNL A839WRR...

Page 40: ...13 AE PCUSUA278WRP0 1 4 12 AB PDUC A833WRPZ 1 4 8 AM PDUC A853WRWZ 1 4 9 AP PHOK A131WRFZ 1 4 1 AL PPACGA176WREZ 1 4 10 AC PSHEPA382WRE0 2 5 2 AH PSHEPB017WREZ 2 5 2 AR PSHEPB021WREZ 2 3 6 AQ PSHEPB096WREZ 2 3 2 2 AT PSHEPB106WREZ 2 3 2 2 AT Q QCNC A019WRZZ 2 3 7 AG QFS TA014WRE0 1 1 12 AG QSW KA045DRZZ 2 3 2 3 AT QSW MA147WRZZ 1 1 1 AG R RC QZA218WRE0 1 1 5 AW RC QZA295WRZZ 1 1 5 AV RLCDSA128DRZZ...

Page 41: ...en permission of the publisher COPYRIGHT XXXX BYSHARP CORPORATION ALL RIGHTS RESERVED No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without prior written permission of the publisher COPYRIGHT XXXX BYSHARP CORPORATION ALL RIGHTS RESERVED 2005 2005SHARP CORP XXS0 XX_E ...

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