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Sharp R-25JTF Service Manual Download Page 48

R-25JT-F

46

COPYRIGHT © 2005 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, me-
chanical, photocopying, recording, or other-
wise, without prior written permission of the
publisher.

Summary of Contents for R-25JTF

Page 1: ...CROWAVE ENERGY INSIDE FRONT COVER BEFORE SERVICING INSIDE FRONT COVER WARNING TO SERVICE PERSONEL 1 MICROWAVE MEASUREMENT PROCEDURE 2 FOREWORD 3 PRODUCT SPECIFICATIONS 4 GENERAL INFORMATION 4 OPERATION 6 TROUBLE SHOOTING GUIDE TEST PROCEDURE 11 TOUCH CONTROL PANEL 21 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE 31 PICTORIAL DIAGRAM 37 CONTROL PANEL CIRCUIT 38 PRINTED WIRING BOARD 39 PARTS LIST 4...

Page 2: ...ansmission 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 Microwave Meas...

Page 3: ...ge capacitors 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 two high voltage capacitor...

Page 4: ...e 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 Mo...

Page 5: ...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 is energized High Voltage Capac...

Page 6: ...et that is properly installed and grounded WARNING Improper use of the grounding plug can result in a risk of electric shock The electrical requirements are 230 208 Volt 60 Hz AC only and 20 Amp or more fused electrical supply It is recommended that a separate circuit serving only this appliance be provided When installing this appliance observe all applicable codes and ordinances If it is necessa...

Page 7: ...OUBLE QUANTITY pad 20 EXPRESS DEFROST pad 21 Ten number pads for time and memory programming 22 SELECTATIME pad 23 STOP CLEAR pad touch to stop operation of oven and clear remaining heating time 24 SELECTAPOWER pad for setting variable power level 25 START pad touch to operate oven after door is closed and time is set 26 SET pad for setting memory 27 CHECK pad for checking memory 28 SIGNAL pad for...

Page 8: ...elled through the waveguide into the cavity feed box and then into the cavity where the food is placed to be cooked 5 Upon completion of the cooking time the oven will revert to the IDLE condition 6 When the door is opened during a cook cycle monitor switches 1 2 door sensing switch secondary interlock switches 1 2 and primary interlock relays 1 2 are activated with the following results The circu...

Page 9: ...TER COOK OFF 2 APPEARS ON DISPLAY OVEN LAMP BLOWER MOTOR 208 230V 60Hz MAGNETRON 1 BM STIRRER MOTOR SM SM H3 H1 MAGNETRON THERMISTOR BLK WHT DOOR SENSING SWITCH A1 A3 B2 B1 A7 RY2 TAB1 TAB2 RY3 OVEN TEMP FUSE B3 OVEN THERMISTOR 1 OVEN THERMISTOR 2 PRIMARY INTERLOCK RELAY 1 PRIMARY INTERLOCK RELAY 2 MONITOR SWITCH 2 MONITOR SWITCH 1 POWER TRANSFORMER 1 CAPACITOR 1 0 94µF CAPACITOR 2 0 94µF POWER TR...

Page 10: ...SW 3 VOLTAGE SELECT SWITCH V S SW 2 SECONDARY INTERLOCK SWITCHE 1 SECONDARY INTERLOCK SWITCHE 2 OL MAGNETRON TEMP FUSE 1 MAGNETRON TEMP FUSE 2 FUSE 20A DISCHARGE RESISTOR 470K 1 2W LINE CROSS CAPACITOR 1 0 F AC250V NOISE SUPPRESSION COIL 3300pF 3300pF NOISE FILTER OVEN LAMP BLOWER MOTOR 208 230V 60Hz MAGNETRON 1 BM STIRRER MOTOR SM SM H3 H1 MAGNETRON THERMISTOR BLK WHT DOOR SENSING SWITCH A1 A3 B2...

Page 11: ...he door goes to a closed position the contacts of the monitor switches 1 2 are opened first then the contacts of the door sensing switch and the secondary interlock switches 1 2 close 3 If the door is opened and the contacts of the primary interlock relay and secondary interlock switch of the same circuit fail to open the monitor fuse blows simultaneously with closing of the monitor switch contact...

Page 12: ...stirrer motors drive stirrer antennas to stir the microwave radiation from the upper and lower waveguides OVEN LAMPS The oven cavity light illuminates the interior of the oven so that food being cooked can be examined visually through the door window without having to open the door The oven lamp is on during the cooking cycle and idle condition SELECT SWITCHES 1 3 The select switch assembly is an ...

Page 13: ...WRKZ 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 two high voltage capacitors 4 Disconnect the leads to the primari...

Page 14: ...s properly except HIGH power functions EE1 Magnetron 1 failure EE2 Magnetron 2 failure EE3 Magnetron 1 and 2 failure EE4 Voltage is too high EE5 Voltage is too low EE6 Oven thermistor 1 failure EE7 Exhaust air temperature is too high EE8 Relay melt short EE9 Maximum time is exceeded EE16 Oven thermistor 2 and Magnetron thermistor are open EE17 Magnetron temperature is too high OFF CONDITION CONDIT...

Page 15: ...EXTREME CAUTION SHOULD BE OBSERVED Power output of the magnetron can be measured by performing a water temperature rise test This test should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following components or wiring silicon rectifier high voltage capacitor and power transformer This test will require a 16 ounce 453cc measuring cup and an accurate m...

Page 16: ...y for a short time and should indicate an open circuit once the capacitor is charged If the above is not the case check the capacitor with an ohmmeter to see if it is shorted between either of the terminals and case If it is shorted replace the capacitor 5 Reconnect all leads removed from components during testing 6 Reinstall the outer case cabinet 7 Reconnect the power supply cord after the outer...

Page 17: ...1 PRIMARY INTERLOCK RELAY RY2 RY3 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block it open 3 Discharge two high voltage capacitors 4 Disconnect two 2 wire leads from the male tab terminals of the Primary Interlock Relay RY2 and or RY3 Check the state of the relay contacts using a ohmmeter The relay contacts should be open If the relay contacts are closed repl...

Page 18: ...acitors 4 A continuity check across the temperature fuse terminals should indicate a closed circuit unless the temperature of the temperature fuse reaches specfied temperature as shown below J TEMPERATURE FUSE TEST 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 ch...

Page 19: ...eck all functions L NOISE FILTER TEST 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 lead wires from the terminal the noise filter Using an ohmmeter check between the terminals as described in the following table If incorrect reading are obtained replace the noise filter 5 Reconnect all leads remov...

Page 20: ...case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 Run the oven and check all functions 2 Control Unit The following symptoms indicate a defective control unit Before replacing the control unit perform the Key unit test Procedure N to determine if control unit is faulty Re connect the power supply cord And check for followings 2 1 In connection with pads a When touc...

Page 21: ...1 11 13 15 19 12 14 16 20 17 18 3 4 5 6 7 8 9 0 G 8 G 7 G 6 G 5 G 4 G 3 G 2 G 1 G 9 G 10 G 11 G 12 2 DOUBLE QUANTITY EXPRESS DEFROST SELECTA TIME SELECTA POWER STOP CLEAR START SET CHECK SIGNAL 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block it open 3 Discharge two high voltage capacitors 4 Disconnect the leads to the primary of the power transformer 5 Ensur...

Page 22: ...tall the outer case cabinet 8 Reconnect the power supply cord after the outer case is installed 9 Run the oven and check all functions 2 Follow the troubleshooting guide given below if indicator does not light up after above check and repairs are finished 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block it open 3 Discharge two high voltage capacitors 4 Discon...

Page 23: ...put relay by IC1 output 12 Door Sensing Switch Circuit This is a circuit for driving IC1 to detect door opening closing 13 Exhaust Air Temperature Detecting Circuit This is a circuit for transmitting output change of thermistor Oven thermistor 1 to IC1 14 Magnetron Temperature Circuit Detect no load or fan lock This is a circuit for transmitting output change of thermistor Magnetron thermistor to ...

Page 24: ...urned to the LSI as one of signals P24 P27 This model has 20 Memory pads When the oven is shipped Memory pad 1 to 10 are set as follows fig 1 Memory No Cook Time Output Power 1 10 sec 100 2 20 sec 100 3 30 sec 100 4 45 sec 100 5 1 min 100 6 1 min 15 sec 100 7 1 min 30 sec 100 8 2 min 100 9 2 min 30 sec 100 0 3 min 100 fig 1 This model has a double quantity pad When the oven is shipped Magnificatio...

Page 25: ...rmation to LSI Door closed L level signal 0V Door opened H level signal 5V 12 AN0 IN Temperature measurement input FAN LOCK THERMISTOR By inputting DC voltage corresponding to the temperature detected by the thermistor this input is converted into temperature by the A D converter built into the LSI 13 14 P55 P54 OUT Magnetron high voltage circuit driving signal To turn on and off the cook relay In...

Page 26: ...nput The internal clock frequency is set by inserting the ceramic filter oscillation circuit with respect to XOUT terminal 31 XOUT OUT Internal clock oscillation frequency control output Output to control oscillation input of XIN 32 VSS IN Connected to GND 33 P27 IN Signal coming from touch key When either one of G 12 line keys on key matrix is touched a corresponding signal out of P30 P31 P32 P33...

Page 27: ...eal data at every one pulse 7 TEST IN Connected to GND 8 VCC IN Connected to 5V 41 48 P17 P10 OUT Segment data signal Signal similar to P21 49 56 P07 P00 OUT Segment data signal Signal similar to P21 57 59 P37 P35 OUT Terminal not used 60 P34 OUT Key strobe signal Signal applied to touch key section A pulse signal is input to P27 P26 P25 and P24 terminals while one of G4 line keys on key matrix is...

Page 28: ...le 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 Conn...

Page 29: ...Ex 345678 times Flashing 0 1sec BUZZER PAD DISPLAY INDICATOR TONE Door close CHECK CHECK No CHECK 82 68 CHECK user total count SIGNAL SIGNAL DOUBLE 34 56 QUANTITY service total count upper figure 3456XX 1 No 1 1 No after 1 sec 34 56 service total count upper figure 2 No 2 2 No after 1 sec 78 service total count lower figure CHECK 2 Practice for checking total operation time Ex 4567 hours Flashing ...

Page 30: ...h stage 1 1 After 10 of total cooking time is passed 9 9 After 90 of total cooking time is passed START A There is no pause OTHER SETTING AND CHECKING PROCEDURE 1 EXPRESS DEFROST T STG1 STG 2 STG3 STG A x T B 1 To set the constants of Express defrost Ex 0 20T 20 40 at 1st stage 0 13T 30 30 at 2nd stage 0 67T 50 20 at 3rd stage Flicker 0 1 sec BUZZER PAD ORDER DISPLAY TONE Door close SET SET NO wit...

Page 31: ... CHECK PROCEDURE FOR ERROR CODE INDICATION EE1 EE2 When the error code EE1 or EE2 is displayed carry out following procedures and find out the defective parts When oscillation is unstable due to defect of upper and or lower magnetron or defective driving circuits error code indications EE1 or EE2 do not function properly CHECK METHOD FOR ERROR CODE INDICATION Put water in a cup and place inside th...

Page 32: ...d Disconnect lead wires to the interlock relay RY2 to avoid operation of lower magnetron circuit Lead wires to the interlock relay RY3 should be connected Reconnect power supply Heating for one minute Temperature of the water increased 1 Yes EE1 should be indicated Lower magnetron its driving circuit and parts on the circuit are normal 1 CHECK OF TEMPERATURE RISE Fill approx 453 CC of water in a m...

Page 33: ...acitors and wait for 60 seconds 2 Don t let the wire leads touch to the followiong parts 1 High voltage parts Magnetron High voltage transformer High voltage capacitor High voltage rectifier assembly and High voltage wire 2 Hot parts Oven lamp Magnetron High voltage transformer and WARNING FOR WIRING 1 Disconnect the power supply cord 2 Make sure that a definite click can be heard when the microwa...

Page 34: ...the thermo contactor between the 1st fin and the 2nd fin 3 Install the magnetron thermistor to the thermistor angle as shown in Figure C 1 4 Hold the magnetron thermistor to the thermistor angle by bending the tab of the thermistor angle 5 Insert the thermistor angle between the 2nd fin and 3rd fin from the upper fin of the upper magnetron and push it until the thermistor angle stops MAGNETRON THE...

Page 35: ...VE LOCK TERMINAL CAN NOT BE REMOVED BYJUST PULLING ON IT THE LOCK LEVER MUST BE RELEASED TO REMOVE THE CONNECTOR FROM THE TERMINAL HOW TO RELEASE THE POSITIVE LOCK CONNECTOR Figure C 2 How to release the positive lock connector 1 Disconnect the power supply cord and then remove outer case and rear cabinet referring to OUTER CASE REAR CABINET AND POWER SUPPLY CORD REMOVAL 2 Open the oven door and b...

Page 36: ...ft up the control unit CONTROL PANEL ASSEMBLY AND CONTROL UNIT REMOVAL upward 12 Now the control unit and control panel frame with key are free CAUTION When installing the control unit into the control panel frame 1 Be careful not to damage any of the components on the control unit 2 When inserting key units ribbon cable through the frame ensure it is not pinched or bent Ensure the control unit is...

Page 37: ...k switches 1 2 are activated with the door closed The horizontal position of the latch hook should be adjusted so that the monitor switches 1 2 are activated with the door closed 6 Secure the screws with washers firmly 7 Check the operation of all switches If all switches have not activated with the door closed loosen two 2 screws and adjust the latch hook position After adjustment check the follo...

Page 38: ...d oven door is not abnormal and do not of themselves indicate a leakage of microwave energy from oven cavity If such were the case your oven could not be equipped with a vent the very purpose of which is to exhaust the vapor laden air from the oven cavity Figure C 4 Door Replacement OUTER CASE CABINET UPPER OVEN HINGE LOWER OVEN HINGE LATCH HEADS 3 Remove choke cover from door panel referring to C...

Page 39: ... Y B R N O R G HIGH VOLTAGE CAPACITOR HIGH VOLTAGE CAPACITOR H V RECTIFIER H V RECTIFIER MAGNETRON LOWER MAGNETRON UPPER POWER TRANSFORMER POWER TRANSFORMER BLU WHT ORG STIRRER MOTOR LOWER MAGNETRON TEMP FUSE 1 150 C OVEN TEMP FUSE 120 C BRN BLK RED BLK BLK ORG STIRRER MOTOR UPPER BLK B L K B L K WHT WHT BLK GRY ORG WHT WHT BLU RED Y L W B L K P N K B L U NC COM P N K O R G W H T NC COM Y L W R E ...

Page 40: ... VREF AN7 AN6 AN5 AN4 AN3 AN2 AN1 AN0 P55 P54 P53 P52 P51 P50 P47 P46 P45 P44 P43 P42 INT1 INT0 RESET P71 P70 XIN XOUT VSS 1 5 15 10 20 25 30 33 P30 P31 P32 P33 P34 P35 P36 P37 P00 P01 P02 P03 P04 P05 P06 P07 P10 P11 P12 P13 P14 P15 P16 P17 P20 P21 P22 P23 P24 P25 P26 P27 32 35 40 45 50 55 60 64 IC1 IZA633DR CF1 CST4 00MGW R80 4 7k R81 4 7k R82 4 7k R83 4 7k R88 4 7k R87 4 7k R86 4 7k R85 4 7k R84...

Page 41: ...1 RY2 B E Q3 C1 ZD1 R2 R101 R70 R1 Q1 Q23 D22 SP1 R40 10 E B E B D21 D101 C10 J9 R102 Q22 C3 CN B 1 3 1 3 CN H R64 9 R63 C63 C62 C4 J6 1 C8 C64 R62 64 60 R84 C60 R60 D70 D23 R4 8 C70 C101 R71 R61 C61 J5 R65 12 1 CN G CN D R66 5 4 IC3 7 J3 J4 6 1 8 9 16 1 3 2 15 Q2 E B R33 R32 R31 1 4 5 8 IC2 R30 Q60 E B CF1 C6 R3 C7 C5 C31 C30 R5 ZD2 3 20 25 33 F R83 C83 R82 C82 40 R81 C81 R80 C80 IC1 50 55 R58 R5...

Page 42: ...ematic diagram 1 AE CONTROL PANEL PARTS 3 1 DPWBFB975WRU0 Control unit R 25JT F 1 BG 3 1A QCNCMA308DRE0 4 pin connector A 1 AC 3 1B QCNCMA312DRE0 3 pin connector B 1 AB 3 1C QCNCMA039DRE0 3 pin connector H 1 AB 3 1D QCNCWA030DRE0 12 pin connector G 1 AE 3 1E QLUGPA012DRE0 Tab terminal TAB1 TAB2 2 AB C1 VCEAB51EW228M Capacitor 2200 uF 25V 1 AE C2 VCKYD11HF104Z Capacitor 0 1 uF 50V 1 AB C3 VCEAB31AW...

Page 43: ...r PKM22EPT 1 AG T1 RTRNPA095DRE0 Touch control transformer 1 AU CT1 RTRN 026CHRE0 Current transformer 1 AH VRS1 2 RH VZA034DRE0 Varistor 10G471K 2 AD ZD1 VHEHZ12B1 1 Zener diode HZ12B1 1 AB ZD2 VHEHZ4A2 1 Zener diode HZ4A2 1 AA 3 2 FPNLCB468WRK0 Control panel frame with key unit 1 AZ 3 2 1 FUNTKA773WRE0 Key unit 1 AT 3 2 2 HDECAA195WRP0 Decoration metal fittings 1 AP 3 2 3 PCUSUA417WRP0 Cushion 1 ...

Page 44: ...RP0 Door case packing 2 AF 5 10 PGID 0024WRF0 Handle guide 4 AC 5 11 PGID 0025WRF0 Handle spacer 1 AC 5 12 PSPA A102WRE0 Door case spacer 2 AE 5 13 XHTS740P08RV0 Screw 4mm x 8mm 9 AG 5 14 FANGKA200WRY0 Latch fixing angle 1 AQ 5 15 FLEVFA019WRY0 Joint lever 1 AP 5 16 LSTPCA002WRM0 Latch head 2 AM 5 17 MLEVPA220WRF0 Head lever 1 AM 5 18 MSPRCA097WRE0 Latch spring 1 AG 5 19 HBDGCA090WRE0 Door badge 1...

Page 45: ...BZA152WREZ Special screw 1 AB 7 14 LX BZA164WREZ Special screw 12 AC 7 15 LX CZA095WREZ Special screw 3 AB 7 16 LX WZA035WRE0 Special washer 1 AB 7 17 XOTS740P10RV0 Screw 4mm x 10mm 3 AB 7 18 XOTS740P08000 Screw 4mm x 8mm 6 AA 7 19 XCHWW40P08000 Screw 4mm x 8mm 2 AB 7 20 XBPS730P50K00 Screw 3mm x 50mm 2 7 21 XJPS740P10000 Screw 4mm x 10mm 3 AA 7 22 XOTWW40P08000 Screw 4mm x 8mm 32 AB 7 23 LX BZA16...

Page 46: ... 8 7 14 7 13 7 14 7 8 7 8 7 2 7 3 7 14 7 8 7 22 7 5 7 14 7 10 7 8 7 21 7 23 7 22 7 23 4 26 7 22 7 22 x 2 7 22 2 2 2 2 1 17 1 6 7 8 7 21 6 8 6 14 7 15 7 17 7 15 4 44 7 2 7 18 7 6 7 17 4 1 7 7 7 11 4 17 4 21 1 14 7 8 4 32 7 6 4 13 7 22 7 17 1 15 1 15 1 3 4 40 1 7 1 3 4 28 6 10 4 29 A1 A2 B 1 16 4 38 4 2 6 6 7 1 2 8 7 1 4 15 4 16 4 39 6 13 1 8 4 45 1 12 1 12 7 18 4 22 7 18 6 6 7 8 1 4 4 34 1 9 D C 1 ...

Page 47: ... 3 1 3 2 3 6 15 Actual wire harness may be different from illustration 6 4 6 16 6 9 6 3 5 15 5 16 5 17 5 18 5 4 5 13 5 13 5 12 5 14 5 9 5 8 5 7 5 6 5 13 5 13 5 2 5 3 5 10 5 5 5 19 5 6 5 5 10 5 11 5 20 To high voltage capacitor To power transformer 6 5 6 7 MISCELLANEOUS DOOR PARTS CONTROL PANEL PARTS ...

Page 48: ...N 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 me chanical photocopying recording or other wise without prior written permission of the publisher ...

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