Sharp R-426HK Service Manual Download Page 46

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R - 4 2 6 H S
R - 4 2 6 H K
R -426HW

NOTES

Summary of Contents for R-426HK

Page 1: ...NG 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 TROUBLESHOOTINGGUIDE 10 TESTPROCEDURE 11 TOUCHCONTROLPANEL 22 COMPONENTREPLACEMENTANDADJUSTMENTPROCEDURE 28 PICTORIALDIAGRAM 35 CPUUNITCIR...

Page 2: ...ion 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 Micr...

Page 3: ...e 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 4 Rec...

Page 4: ...nter of the 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 ...

Page 5: ...t 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 Cap...

Page 6: ...responsibilityandobligationofthecustomertocontact SPECIFICATION ITEM DESCRIPTION PowerRequirements 120 Volts 14 3 Amperes 1700 watts 60 Hertz Single phase 3 wire grounded PowerOutput 1200 watts IEC 705 TEST PROCEDURE Operatingfrequencyof2450MHz CaseDimensions Width 21 21 32 Height 12 3 8 Depth 18 7 16 Cooking Cavity Dimensions Width 15 23 32 Height 9 21 32 1 6 Cubic Feet Depth 17 7 8 ControlComple...

Page 7: ... The oven will not operate unless the door is securely closed 3 Removable turntable support 4 Removable turntable The turntable will rotate clockwise or counterclockwise 5 Oven lamp It will light when oven is operating or door is opened 6 Oven door with see through window 7 Ventilation openings Rear 8 Auto Touch control panel 9 Time display Digital display 99 minutes 99 seconds 10 Wave guide cover...

Page 8: ...uits to the turntable motor the cooling fan motor and the high voltage componentsarede energized theovenlampremainson andthedigitalread outdisplaysthetimestillremainingin the cook cycle when the door was opened 7 The monitor switch electrically monitors the operation of theprimaryinterlockswitchandsecondaryinterlockrelay andismechanicallyassociatedwiththedoorsothatitwill function in the following ...

Page 9: ...ing Sequence 1 Touch one of the SENSOR pads NOTE The oven should not be operated on sensor immediately after plugging in the unit Wait two minutes before cooking on SENSOR 2 The coil of shut off relay RY 1 is energized the turntablemotorareturnedon butthepowertransformer is not turned on 3 Afterabout16seconds thecookrelay RY 2 isenergized The power transformer is turned on microwave energy is prod...

Page 10: ...OTOR OVEN LAMP MONITOR SWITCH PRIMARY INTERLOCK SWITCH POWER TRANSFORMER MAGNETRON HIGH VOLTAGE CAPACITOR ORG WHT SECONDARY INTERLOCK RELAY ORG BRN ORG ORG RED RED GRY GRY GND WHT F3 F2 F1 SENSOR RY1 OVEN LAMP RELAY COM N O HUMIDITY COM N C HIGH VOLTAGE RECTIFIER ORG CAVITY TEMPERATURE FUSE 120VAC 60Hz COM RED RED WHT WHT WHT WHT BRN WHT WHT WHT ORG RED WHT WHT GRN N O B2 B1 CONTROL UNIT N O RY2 C...

Page 11: ...il to open the C T fuse blows simultaneously with closing of the monitor switch contacts CAUTION BEFORE REPLACING A BLOWN C T FUSE TEST THE DOOR SENSING SWITCH SEC ONDARY INTERLOCK RELAY RY2 RELAY RY1 PRIMARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPERA TION REFER TO CHAPTER TEST PROCE DURE NOTE C T FUSE AND MONITOR SWITCH ARE REPLACED AS AN ASSEMBLY TURNTABLE MOTOR The turntable motor rot...

Page 12: ...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 the primary of the power tr...

Page 13: ...ood incompletely cooked or not cooked at all at end of cook cycle Oven goes into a cook cycle but extremely uneven heating is pro duced in oven load food Oven does not cook properly when programmed for Cooking Power P 50 mode Operates properly on Cooking P HI HIGH mode Oven goes into COMPU DEFROST but food is not defrosted well AH sensor does not end during sensor cooking condition Oven does not s...

Page 14: ...O EXTREME CAUTION SHOULD BE OBSERVED Power output of the magnetron can be measured by performing a water temperature rise test This test shouldonlybeusedifabovetestsdonotindicateafaultymagnetronandthereisnodefectinthefollowing componentsorwiring siliconrectifier highvoltagecapacitorandpowertransformer Thistestwillrequire a 16 ounce 453cc measuring cup and an accurate mercury thermometer or thermoc...

Page 15: ...ol unit Check for restricted air flow through the vent holes of the oven cavity 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 C T FUSE TEST 1 Disconnect the power supply cord and then remove outer case ...

Page 16: ...on and the door is closed the cooling fan turntable and oven light will be activated by RY1 SECONDARYINTERLOCKRELAY RY2 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 Disconnecttwo 2 wireleadsfromthemaletabterminalsoftheSecondaryInterlockRelay Checkthe state of the relay contacts using a ohmmeter The relay contac...

Page 17: ...using the ohmmeter as follows When the door is open the meter should indicate a closed circuit When the monitor switch actuator is pushed by a screw driver through the lower latch hole on the front plate of the oven cavity withthedooropened inthisconditiontheplungerofthemonitorswitchispushedin themetershould indicate an open circuit If improper operation is indicated the switch may be defective Af...

Page 18: ...2 ControlUnit The following symptoms indicate a defective control unit 2 1 In connection with pads a When touching the pads a certain group of pads do not produce a signal b When touching the pads no pads produce a signal 2 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 d The corre...

Page 19: ...pacitor 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 Removetheoutercaseandcheckvoltagebetweenthenormalopen terminaloftherelayRY1and the normal open terminal of the relay RY2 on the control unit with an A C voltmeter Th...

Page 20: ... 20sec 30 45sec 8 If improper operation is indicated the control unit is probably defective and should be checked 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 it open 3 Dischar...

Page 21: ...re should not exceed 95 F 35 C 3 The unit should not be installed in any area where heat and steam are generated The unit should not be installed for example next to a conventional surface unit Refer to the INSTALLATION INSTRUCTIONS oftheoperationmanual 4 Exhaustventsareprovidedonthebackoftheunitforpropercoolingandairflowinthecavity Topermit adequate ventilation be sure to install so as not to blo...

Page 22: ...TART pad 9 5 The control panel is in automatic Sensor operation 9 6 The oven turns off automatically and the time for detecting moisture will be displayed Ifnewsensordosenotoperateproperly theproblemiswiththecontrolunit andrefertoexplanationbelow CHECKINGCONTROLUNIT 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 ...

Page 23: ...uter case is installed Run the oven and check all functions 18 Carry out Water load cooking test again and ensure that the oven works properly R1 R2 22Ω Ω Ω Ω Ω 1 1 2W R3 4 3Ω Ω Ω Ω Ω 5 1 4W R4 1MΩ Ω Ω Ω Ω 5 1 4W Sensor Dummy Resistor Circuit TEST PROCEDURES PROCEDURE LETTER COMPONENTTEST Plunger NC NO COM COM NO NC R3 R4 R1 R2 1 2 3 F 1 F 2 F 3 To connector F on Control Unit CONNECTOR ...

Page 24: ...supplied 2 IndicatorCircuit This circuit consists of 25 segments and 4 common electrodes using a Liquid Crystal Display 3 Power Source Circuit This circuit generates voltages necessary in the control unit from the AC line voltage In addition the synchronizing signal is available in order to compose a basic standard time in the clock circuit Symbol Voltage Application VC 5V LSI IC1 4 RelayCircuit A...

Page 25: ...uzzer 2 0 kHz A key touch sound B Completion sound 15 P53 OUT Used for initial balancing of the bridge circuit absolute humidity sensor 16 P52 OUT Oven lamp fan motor and turntable motor driving signal To turn on and off shut off relay RY1 The square waveform voltage is delivered to the RY1 driving circuit and RY2 control circuit 17 P51 OUT Used for initial balancing of the bridge circuit absolute...

Page 26: ...obe signal Signal applied to touch key section A pulse signal is input to P70 P71 P41 P45 P47 and AN3 terminal while one of G7 line keys on key matrix is touched 35 P25 OUT Key strobe signal Signal applied to touch key section A pulse signal is input to P70 P71 P41 P45 P47 and AN3 terminal while one of G6 line keys on key matrix is touched 36 P24 OUT Key strobe signal Signal applied to touch key s...

Page 27: ...G11 61 SEG 11 SEG24 48 SEG 24 SEG12 60 SEG 12 73 VCC IN Power source voltage GND 0V 74 VREF IN A D converter power source voltage GND 0V The power source voltage to drive the A D converter Connected to GND 75 AVSS IN A D converter power source voltage 5 0V The power source voltage to drive the A D converter Connected to VC 76 COM3 OUT Common data signal Connected to LCD signal COM0 77 COM2 OUT Com...

Page 28: ...ge the resistance values in parallel with R98 R102 Changing the resistance values results in that there is the same potential at both F 3 terminal of the absolute humidity sensor and AN0 terminal of the LSI The voltage of AN1 terminalwillindicateabout 2 5V Thisinitialbalancingis setupabout16secondsaftertheunitisputintheSensor Cooking mode As the sensor cooking proceeds the foodisheatedtogeneratemo...

Page 29: ...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 Toolsrequiredtoservicethetouchcontrolpanelassembly 1 Solderingiron 30W Itisrecommendedtouseasolderingironwithagrounding terminal 2 Oscilloscope Singlebeam frequencyrang...

Page 30: ... the power supply cord 2 Make sure that a definite click can be heard when the microwave oven door is unlatched Hold the door in a closed position with one hand then push the door open button with the other this causes the latch leads to rise it is then possible to hear a click as the door switches operate 3 Visuallycheckthedoorandcavityfaceplatefordamage dents cracks signs of arcing etc Carry out...

Page 31: ...nt lead short one of the power transformer from the high voltage capacitor 7 Remove one 1 screw holding capacitor holder with the high voltage rectifier to the base plate 8 Disconnect rectifier terminal from capacitor High voltage rectifier assembly is now free 9 Remove capacitor holder Capacitor is now free CAUTION WHEN REPLACING HIGH VOLTAGE RECTI FIER AND HIGH VOLTAGE CAPACITOR GROUND SIDE TERM...

Page 32: ...yunit wipeoff remaining adhesive on the control panel frame surfaces completely with a soft cloth soaked in alcohol 2 When attaching the key unit to the control panel frame adjusttheupperedgeandrightedgeofthe key unit to the correct position of control panel frame 3 Placethekeyunitfirmlytothecontrolpanelframe by rubbing with soft cloth not to scratch 1 Disconnect the power supply cord and remove o...

Page 33: ...on on the surface of the control panel frame 5 Attach the graphic sheet to the control panel frame by rubbing with a soft cloth not to scratch 6 Reinstall the control panel frame to the oven NOTE Do not touch the contact surface of the ribbon cable edge and the rubber connector with a finger directly not to be oxidized If display digits are missing or scrambled remove control unit and make sure th...

Page 34: ... after installation Make sure that the axis of the shaft is not slanted 5 Install the fan motor to the oven cavity back plate with the two 2 screws 6 Connect the wire leads to the fan motor referring to the pictorial diagram DOORSENSINGSWITCH PRIMARYINTERLOCKSWITCHANDMONITORSWITCHREMOVAL Rear View Side View Gap Rotor Bracket Stator Groove joint pliers Coil Shaft Axis Stator Rotor These are the pos...

Page 35: ...oosen screw and adjust the latch hook position After adjustment check the following 1 In and out play of door remains less than 0 5mm when in the latched position First check upper position of latch hook pushing and pulling upper portion of door toward the oven face Then check lower portion of the latch Figure C 3 Latch Switch Adjustments hook pushing and pulling upper portion of door toward the o...

Page 36: ... emission limitation standards After any service make sure of the following 1 Door latch heads smoothly catch latch hook through latch holes and that latch head goes through center of latch hole 2 Deviation of door alignment from horizontal line of cavity face plate is to be less than 1 0mm 3 Doorispositionedwithitsfacepressedtowardcavityface plate 4 Checkformicrowaveleakagearounddoorwithanapprove...

Page 37: ...inal with blue mark on the oven light socket POWER TRANSFORMER COM NO NOTE The neutral WHT GRY wire must be connected to the terminal with N mark on the power supply cord RED WHT BRN RED WHT WHT ORG WHT RED RED PNK GRN GRN to Oven cavity WHT WHT WHT WHT BLUE MARK RED WHT CAVITY TEMP FUSE FAN MOTOR C T FUSE RED RED WHT GRY WHT GRN ORG ORG RY2 RY1 SECONDARY INTERLOCK RELAY T1 1 2 POWER UNIT H N NOTE...

Page 38: ... MEAT DEFROST STEAKS CHOPS BONE IN POULTRY FRESH ROLLS MUFFINS FROZEN ENTREES BONELESS POULTRY STOP CLEAR SENSOR REHEAT POPCORN FROZEN VEGETABLES RICE CHICKEN BREAST BEVERAGE BAKED POTATOES GROUND MEAT SENSOR COOK CUSTOM HELP TIMER CLOCK HOT WATER R110 15K R80 P41 P40 RESET P71 P70 XIN XOUT VSS P27 P26 P25 P24 P23 P22 P21 P20 VL3 COM0 COM1 COM2 COM3 AVSS VREF VCC SEG0 SEG1 SEG2 SEG3 SEG4 SEG5 SEG6...

Page 39: ... B C D E F G H Figure S 5 Printed Wiring Board of Power Unit RY1 RY2 E C B E C B E C B VRS1 L1 D7 D3 P S D4 C2 D1 C1 D2 R8 R7 R2 R4 Q3 Q4 SP1 T1 D6 DZ1 WH 2 WH 2 LED Q2 D5 D8 D30 1 2 J1 J6 J2 J5 R5 C4 C5 CN B CN F 1 2 3 C10 DIP CHIP SIDE R90 J3 D31 R3 R6 E B 1 1 2 2 Q1 ...

Page 40: ...M Control panel frame R 426HW 1 AE 3 3 PSHEPB109MRR0 M Key unit R 426HS HK 1 AG 3 3 PSHEPB119MRR0 M Key unit R 426HW 1 AG 3 4 FDECAB037MRK0 M Open button R 426HS 1 AF 3 4 JBTN B146MRF0A M Open button R 426HK 1 AD 3 4 JBTN B153MRF0A M Open button R 426HW 1 AE 3 5 MSPRTA050WRE0 M Open button spring 1 AA 3 6 XEPSD30P06XS0 M Screw 3mm x 10mm 5 AB OVEN PARTS 4 1 LBNDKB007MRP0 M H V Capacitor band 1 AB ...

Page 41: ...MRE0 M Main wire harnes 1 AU 6 3 FROLPB025MRK0 M Turntable support 1 AN 6 4 NTNT A108WREZ M Turntable tray 1 AM 6 5 TCAUAB045MRR0 M Monitor caution label 1 AA 6 6 TCAUAB038MRR0 M DHHS Screw caution label 1 AB 6 7 TINSEB326MRK0 M Operation manual 1 AD 6 8 QW QZB016MRE0 M High voltage wire A 1 AC SCREWS NUTSANDWASHERS 7 1 LX BZA041WRE0 M Special screw 5 AA 7 2 LX CZ0052WRE0 M Special screw 2 AA 7 3 ...

Page 42: ...B C D E F G H OVEN AND CABINET PARTS 2 3 4 7 6 6 1 5 4 6 4 8 4 9 6 4 6 3 2 1 7 5 1 10 4 10 7 2 7 2 7 4 4 3 1 11 1 8 7 3 7 6 7 5 7 7 4 2 7 4 1 9 1 3 1 4 7 1 1 7 1 7 4 4 7 1 4 1 1 1 1 2 2 2 2 2 2 2 2 2 7 4 7 4 4 11 7 4 6 5 1 6 4 5 1 12 7 8 7 6 7 8 7 6 1 6 4 12 7 2 7 5 1 13 ...

Page 43: ... 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 CONTROL PANEL PARTS 5 1 2 5 1 1 5 5 5 4 5 3 5 2 5 8 5 1 5 6 5 7 3 3 3 2 3 5 3 1 3 4 3 6 Actual wire harness may be different from illustration 6 8 6 2 6 1 DOOR PARTS MISCELLANEOUS ...

Page 44: ... AND ACCESSORIES DOOR PROTECTION SHEET PLASTIC BAG PACKING CASE TOP PAD ASSEMBLY INTO THE OVEN CAVITY 6 4 TURNTABLE TRAY 6 7 OPERATION MANUAL BOTTOM PAD ASSEMBLY TRAY HOLDER 6 3 TURNTABLE SUPPORT ON TOP OF THE OVEN Non replaceable items ...

Page 45: ...43 R 426HS R 426HK R 426HW NOTES ...

Page 46: ...44 R 426HS R 426HK R 426HW NOTES ...

Page 47: ...45 R 426HS R 426HK R 426HW NOTES ...

Page 48: ...HT 2003 BY SHARP CORPORATION ALL RIGHTS RESERVED No part of this publication may be repro duced stored in retrieval systems or trans mitted in any form or by any means elec tronic mechanical photocopying recording orotherwise withoutpriorwrittenpermission of the publisher ...

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