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15

R-300BW

c) Only one LED does not light up.
d) All or some LEDs continue to light up.
e) A certain group of LEDs do not light up.

f) The LEDs flicker.

1-2 Other possible troubles caused by defective control unit.

a) Buzzer does not sound or continues to sound.
b) Clock is not possible.
c) Cooking time can not be set.
d) Power level can not be set.

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 outer case is installed.
7) Run the oven and check all functions.

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

J

RELAY 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 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. Remove the outer case and check voltage between Pins No. 3 and 5 of the 3 pin connector (A) on

the control unit with an A.C. voltmeter.

The meter should indicate 120 volts, if not check oven circuit.

RY1 Relay Test

These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking 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.

RELAY SYMBOL

OPERATIONAL VOLTAGE

CONNECTED COMPONENTS

RY1

Approx. 12.5V D.C.     

(*)

Oven lamp / Turntable motor / Cooling fan motor

RY2

Approx. 12.5V D.C.     

(*)

Power transformer

(*) The voltage under the condition when all LEDs light up.

8. Disconnect the power supply cord and then remove outer case.
9. Open the door and block it open.
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.

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.

K

FOIL PATTERN ON THE PRINTED WIRING BOARD TEST

Summary of Contents for R-300BW

Page 1: ...XPOSURE 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 CONTROL PANEL 17 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE 21 PICTORIAL DIAGRAM 27 CONTROL PANEL CIRCUIT 28 PRINT...

Page 2: ...d 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 releasing oven to the owner BEFORE SERVICING Before servicing an operative unit perform a microwave emission check as per the Mic...

Page 3: ...pacitor 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 Reconne...

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: ...amaged 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 DANGER Certaininitialpartsareintentionallynotgroundedandpresent a risk of electrical shock only during servicing Service personnel Do not contact the following parts while the appliance is energized HighVoltageCapacitor Po...

Page 6: ...de and local codes and ordinances In the event of an electrical short circuit grounding reduces the risk of electric shock by providing an escape wire for the electric current WARNING Improper use of the grounding plug can result in a risk of electric shock Electrical Requirements The electrical requirements are a 115 120 volt 60 Hz AC only 15 or 20 amp fused electrical supply It is recommended th...

Page 7: ...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 Control panel 9 Coupling 10 Wave guide cover 11 Power supply cord 4 3 CONTROL PANEL 1 10 9 5 6 2 8 11 7 MED DEFROST MED LOW LOW MED HIGH HIGH 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30 COOKING CONTROL Light Up D...

Page 8: ... the turntable motor the cooling fan motor and the high voltage components are de 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 f...

Page 9: ...C 2000V MONITOR SWITCH RECTIFIER MAGNETRON SECONDARY INTERLOCK SWITCH TTM OL FM MONITOR FUSE 15A A5 A3 COM N O DOOR SENSING SWITCH RY 1 RY 2 CONTROL UNIT PRIMARY INTERLOCK RELAY THERMAL CUT OUT OVEN THERMAL CUT OUT MG B2 A1 B1 GRN POWER TRANSFORMER RECTIFIER MAGNETRON CAPACITOR 0 94µF AC 2000V 120V AC 60 Hz OVEN LAMP TURN TABLE MOTOR FAN MOTOR MONITOR SWITCH SECONDARY INTERLOCK SWITCH TTM OL FM MO...

Page 10: ...y RY2 and secondary interlock switch contacts fail to open themonitorfuseblowssimultaneouslywithclosing of the monitor switch contacts CAUTION BEFORE REPLACING A BLOWN MONITOR FUSE TEST THE DOOR SENSING SWITCH PRIMARY INTERLOCK RELAY RY2 SEC ONDARY INTERLOCK SWITCH AND MONI TOR SWITCH FOR PROPER OPERATION REFERTOCHAPTER TESTPROCEDURE NOTE MONITOR FUSE AND MONITOR SWITCH ARE REPLACED AS AN ASSEMBLY...

Page 11: ...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 12: ...k cycle Oven goes into a cook cycle but extremely uneven heating is produced in oven load food Oven does not cook properly when pro grammed for variable cooking mode Op erates properly on Cooking Power HIGH mode OFF CONDITION PROBLEM CONDITION SHORT IN POWER CORD SHORT OR OPENED WIRING MAGNETRON POWER TRANSFORMER H V RECTIFIER ASSEMBLY HIGH VOLTAGE CAPACITOR THERMAL CUT OUT SECONDARY INTERLOCK SWI...

Page 13: ...OK CYCLE SO 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 ...

Page 14: ...n 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 MAGNETRON THERMAL CUT OUT TEST 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block it open 3 Discharge high vol...

Page 15: ...rom 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 NOTE If the door sensing switch contacts fail in the open position and the door is closed the cooling fan turntable and oven light will be activated by RY1 PRIMARY INTERLOCK RELAY RY2 1 Disconnect the power supply cord and then ...

Page 16: ...st be replaced with monitor fuse and monitor switch assembly part number FFS BA010WRK0 even if the monitor switch operates normally The monitor fuse and monitor switch assembly is comprised of a 15 ampere fuse and switch 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 ...

Page 17: ...outer case and check voltage between Pins No 3 and 5 of the 3 pin connector A on the control unit with an A C voltmeter The meter should indicate 120 volts if not check oven circuit RY1 Relay Test These relays are operated by D C voltage Check voltage at the relay coil with a D C voltmeter during the microwave cooking operation DC voltage indicated Defective relay DC voltage not indicated Check di...

Page 18: ...t 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 7 Follow the troubleshooting guide given below for repa...

Page 19: ...kes setting of the power level by variable resistance Control Unit Control unit consists of LSI power source circuit synchro nizing signal circuit ACL circuit buzzer circuit encoder circuit indicator circuit and potentiometer circuit 1 LSI This LSI controls the encoder signal potentiometer signal relay driving signal for oven function buzzer signal and LED signal 2 Power Source Circuit This circui...

Page 20: ... NC No connection terminal 9 S0 OUT Digit selection signal Signal is input to the anodes of the light emitting diodes LD19 LD24 10 S1 OUT Digit selection signal Signal is input to the anodes of the light emitting diodes LD13 LD18 11 S2 OUT Digit selection signal Signal is input to the anodes of the light emitting diodes LD7 LD12 12 S3 OUT Digit selection signal Signal is input to the anodes of the...

Page 21: ...deliv ered to the relay RY1 driving circuit and relay RY2 control circuit 26 NC No connection terminal 27 F0 IN Input signal which communicates the door open close information to LSI Door closed H level signal Door opened L level signal 28 F1 Terminal not used 29 F2 IN Signal to synchronize LSI with commercial power source frequency This is basic timing for all real time processing of LSI 30 F3 IN...

Page 22: ... 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 4 Servicing Tools Tool...

Page 23: ...R WIRING 1 Disconnect 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...

Page 24: ...cle into terminal insulator 2 Close covers of the terminal insulator as shown below 3 Reconnect all leads removed from components during testing 4 Reinstall the outer case cabinet 5 Reconnect the power supply cord after the outer case is installed 6 Run the oven and check all functions Terminal insulator Flat type screw driver RECEPTACLE COVERS TERMINAL INSULATOR REPLACEMENT Special screw Screw Dr...

Page 25: ...g chassis support to magnetron 6 Remove the chassis support from oven 7 Carefully remove the four 4 screws holding magnetron to waveguide flange 8 Lift up magnetron with care so that magnetron antenna is not hit by any metal object around antenna 9 Now the magnetron is free Re install 1 Re install the magnetron to waveguide flange with the four 4 screws as shown in Figure C 1 2 Insert the two 2 ta...

Page 26: ...he fan motor is free INSTALLATION 1 Install the fan motor to the fan duct with the two 2 screws 2 Install the fan blade to the fan motor shaft according to the following procedure 3 Hold the center of the bracket which supports the shaft of the fan motor on the flat table 4 Apply the screw lock tight into the hole for shaft of the fan blade 5 Install the fan blade to the shaft of fan motor by push...

Page 27: ...outer case and check for microwave leakage around door with an approved microwave survey meter Refer to Microwave Measurement Procedure Latch Hook Door Sensing Switch Monitor Switch Secondary Interlock Switch Switch Lever Latch Heads Door Figure C 4 Latch Switch Adjustments 1 Disconnect the power supply cord and remove outer case 2 Open the door and block it open 3 Discharge high voltage capacitor...

Page 28: ...Procedures B An approved microwave survey meter should be used to assure compliance with proper microwave radiation 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...

Page 29: ...n the oven light socket H N POWER TRANSFORMER COM NO NOTE The grounding conductor of the power supply cord has been grounded by power supply cord fixing screw The screw must allways be kept tight NOTE The neutral WHT wire must be connected to the terminal with N mark on the power supply cord BLK GRY RED WHT BLK WHT BLK BLK GRY GRN GRN R E D WHT GRY BLK BLK WHT BLUE MARK BLK BLK OVEN THERMAL CUT OU...

Page 30: ...Q51 DTB123ES Q52 DTB123ES R1 100 2w D1 D4 11ES1 D1 D3 T1 J1 CN A a b d c AC120V 60Hz A 5 A 1 A 3 NO COM B 1 B 2 A D4 D2 Q1 2SB1238 Q2 DTA123ES 0 V Q40 DTA143ES Q20 DTA143ES JE IF NOT SPECIFIED 1 4w 5 IF NOT SPECIFIED 1SS270A IF NOT SPECIFIED 0 01µF 16v RY1 A RY2 Q21 DTD143ES Q22 DTA143ES Q53 DTB123ES 150 LD1 LD7 LD13 LD19 LD2 LD8 LD14 LD20 LD3 LD9 LD15 LD21 LD4 LD10 LD16 LD22 LD5 LD11 LD17 LD18 LD...

Page 31: ...R6 R7 JD 41 WH A WH A RY3 RY2 33 R30 R20 C4 C5 C21 F LD21 LD22 LD23 LD24 LD17 SW1 R60 R61 R63 7 8 12 11 26 27 D5 D30 R31 R5 R4 R40 R10 ZD1 ZD3 39 C2 D4 D3 RY1 VRS1 VR1 CN A D2 D1 T1 S P 1 5 JC R22 40 JE ZD2 B B B B B E E E E GRILL MICRO DIP E Q2 Q40 Q22 Q20 Q10 CN B Q23 C20 SP1 C30 CF1 28 29 31 35 38 34 1 2 37 32 C3 JB 25 24 23 22 21 20 19 13 14 15 16 17 18 Q50 Q51 Q52 Q53 E E E E R50 R51 R52 R53 ...

Page 32: ...34DRE0 Lead wire WH A 1 AD C1 VCEAB31VW477M Capacitor 470uF 35V 1 AC C2 RC KZA087DRE0 Capacitor 0 1uF 50V 1 AA C3 VCKYD11CY103N Capacitor 0 01uF 16V 1 AA C4 VCEAB31CW476M Capacitor 47uF 16V 1 AA C5 RC KZA087DRE0 Capacitor 0 1uF 50V 1 AA C6 VCKYD11CY103N Capacitor 0 01uF 16V 1 AA C20 VCEAB31HW104M Capacitor 0 1uF 50V 1 AM C21 VCEAB31VW106M Capacitor 10uF 35V 1 AA C30 VCKYD11CY103N Capacitor 0 01uF ...

Page 33: ...ch lever 1 AF 4 12 NCPL A045WRF0 Coupling 1 AH 4 13 PCUSGA353WRP0 Cushion 1 AH 4 14 PCOVPA275WRE0 Waveguide cover 1 AR 4 15 PCUSGA339WRP0 Cushion 1 AG 4 16 PCUSUA212WRP0 Cushion 1 AB 4 17 PCUSUA235WRP0 Cushion 1 AF 4 18 GCOVHA385WRF0 Choke cover 1 AG DOOR PARTS 5 1 FDORFA318WRT0 Door panel 1 BE 5 2 PSHEPA382WRE0 Sealer film 1 AH 5 3 GWAKPA549WRR0 Door frame 1 AZ 5 4 HPNL A690WRR0 Door screen 1 AT ...

Page 34: ...orized SHARP parts Distributor for your area Defective parts requiring return should be returned as indicated in the Service Policy 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 5 2 5 7 5 1 5 3 5 6 Actual wire harness may be different from illustration 6 4 6 3 CAPACITOR 5 4 6 5 5 8 5 5 4 18 3 9 3 8 3 5 3 1 3 2 3 4 3 10 3 10 3 3 3 6 3 10 3 10 6 9 3 7 MISCELLANEOUS DOOR PARTS CONTROL PANEL...

Page 35: ...7 8 7 5 7 7 2 1 4 1 6 11 7 2 4 16 7 4 7 6 7 3 6 2 7 3 7 6 1 1 1 1 1 2 4 8 1 7 4 4 7 5 7 5 7 1 6 9 4 3 7 5 6 1 7 1 1 9 4 6 1 8 6 6 4 17 1 4 4 7 6 7 1 5 4 12 4 14 1 12 7 1 4 2 4 15 1 14 4 13 2 3 4 5 1 3 1 6 7 1 7 6 7 6 7 6 7 6 7 6 2 5 2 4 7 6 7 6 2 4 7 6 2 2 4 11 4 9 4 10 1 13 7 1 7 3 6 10 1 11 1 10 6 11 ...

Page 36: ...RNTABLE TRAY 6 8 INSTRUCTION BOOK PRINTING MATTER 6 1 TURNTABLE SUPPORT TRAY PACK SPADFA397WRE0 INTO THE OVEN CAVITY COPYRIGHT 1998 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 record ing or otherwise without prior written per mission of the publish...

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