Sharp R-21LTF - Oven Microwave 1000 W Service Manual Download Page 18

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R21LTF

8 – 6

[13] Procedure L: 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 Pin Numbers. 3 and 7 of the connector (A) on the control unit with an A.C. voltmeter.

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

RY2 and RY3 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.

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.

[14] Procedure M: FOIL PATTERN ON THE PRINTED WIRING BOARD 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 it open.

3) Discharge high voltage capacitor.

4) Follow the troubleshooting guide given below for repair.

RELAY SYMBOL

OPERATIONAL VOLTAGE

CONNECTED COMPONENTS

RY2

Approx. 12.0V D.C.

Power transformer

RY3

Approx. 12.0V D.C.

Oven lamp / Antenna motor / Cooling fan motor

STEPS

OCCURRENCE

CAUSE OR CORRECTION

SELECTA

TIME

SELECTA

POWER

STOP/

CLEAR

START

SET

CHECK

SIGNAL

DOUBLE

QUANTITY

EXPRESS

DEFROST

G12

G11

G10

G 9

G 1

G 2

G 3

G 4

G 5

G 6

G 7

G 8

SELECTA

TIME

STOP/

CLEAR

START

SET

CHECK

SIGNAL

DOUBLE

QUANTITY

EXPRESS

DEFROST

G12

G11

G10

G 9

G 1

G 2

G 3

G 4

G 5

G 6

G 7

G 8

R-21LTF

R-21LVF

Summary of Contents for R-21LTF - Oven Microwave 1000 W

Page 1: ... S7606R21LTFP LIGHT DUTY COMMERCIAL MICROWAVE OVEN R 21LTF R 21LVF SERVICE MANUAL R21LTF 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 original condition and only parts identical to those specified should be used WARNING TO...

Page 2: ...L PANEL ASSEMBLY TEST 8 4 12 Procedure K KEY UNIT TEST 8 5 13 Procedure L RELAY TEST 8 6 14 Procedure M FOIL PATTERN ON THE PRINTED WIRING BOARD TEST 8 6 CHAPTER 9 TOUCH CONTROL PANEL ASSEM BLY 1 OUTLINE OF TOUCH CONTROL PANEL 9 1 2 SERVICING FOR TOUCH CONTROL PANEL 9 1 3 PROCEDURE FOR CHECKING CLEAR ING SERVICE COUNTS OF MICRO WAVE OVEN 9 2 4 OTHER SETTING AND CHECKING PRO CEDURE 9 3 CHAPTER 10 P...

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: ...gh 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 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 capa...

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: ...ackets 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 the...

Page 7: ...omplement Touch Control System 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 FULL Power P 20 approx 20 of FULL Power P 10 appro...

Page 8: ...ter 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 PRONG FROM THIS PLUG 2 OVEN DIAGRAM 1 OVEN 1 Back splash cover 2 Side splash cover 3 Oven light 4 C...

Page 9: ...cook cycle when the door was opened 7 The monitor switch electrically monitors the operation of the sec ondary interlock switch and control relay RY3 and is mechanically 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 their contacts And contacts of the rela...

Page 10: ...L AC120V 60 Hz POWER TRANSFORMER CAPACITOR 1 00 μF 2300V DOOR SENSING SWITCH SECONDARY INTERLOCK SWITCH CONTROL UNIT THERMAL CUT OUT 125ºC OVEN THERMAL CUT OUT 145ºC MAG PRIMARY INTERLOCK RELAY CONTROL RELAY MONITOR SWITCH MAGNETRON RECTIFIER RY3 RY2 A3 A7 B1 B2 OL FM AM OVEN LAMP FAN MOTOR ANTENNA MOTOR FUSE LINE CROSS CAPACITOR 0 22μF AC250V NOISE SUPPRESSION COIL LINE BYPASS CAPACITOR 0 0033μF ...

Page 11: ...eously with closing of the monitor switch contacts CAUTION BEFORE REPLACING A BLOWN MONITOR FUSE TEST THE DOOR SENSING SWITCH PRIMARY INTERLOCK RELAY RY2 RELAY RY3 SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPER ATION REFER TO CHAPTER TEST PROC NOTE MONITOR FUSE AND MONITOR SWITCH ARE REPLACED AS AN ASSEMBLY 4 ANTENNA MOTOR The antenna motor rotates the stirrer antenna located on the...

Page 12: ...mer 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 Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected TEST PROCEDURE CONDITION PROBLEM POSSIBLE CASE AND DEFECTIVE PARTS Home fuse or circuit breaker blows when power cord is...

Page 13: ...erature making sure 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 be 34 7 to 64 6 F 19 3 to 35 9 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 magn...

Page 14: ...hermal cut out and check inside of oven cavity and for improper setting of cooking time or operation of control 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 ...

Page 15: ... 7 Reconnect the power supply cord after the outer case is installed 8 Run the oven and check all functions 8 Procedure G MONITOR SWITCH 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 Before performing this test make sure that the secondary interlock switch and the primary interlock relay are operating prope...

Page 16: ...he 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 ohmmeter In this service manual the touch control panel assembly is divided into two units Control Unit and Key Unit and troubleshooting by unit replacement is described according to the symptoms indi...

Page 17: ...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 12 Procedure K KEY UNIT 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 If the display f...

Page 18: ...igh 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 14 Procedure M FOIL PATTERN ON THE PRINTED WIRING BOARD TEST To protect the electronic circuits this model is provided with a fine foil pattern added to the primary on th...

Page 19: ... 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 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 cab...

Page 20: ...ory pad 1 to 10 are set as follows fig 1 This model has a double quantity pad When the oven is shipped Magnification 1 7 is preset in the double quantity pad This model has an express defrost pad When the oven is shipped express defrost is set as follows fig 2 When 1 2 total cooking time is passed the signal will sound and CHECK indicator will flash 2 SERVICING FOR TOUCH CONTROL PANEL 1 Precaution...

Page 21: ...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 60W It is recommended to use a soldering iron with a grounding termi nal 2 Oscilloscope Single beam frequency range DC 10MHz type or more advanced model 3 Others Hand tools 4 Other Precautions 1 Bef...

Page 22: ...AL DOUBLE 34 56 QUANTITY service total count upper figure 3456XX 2 2 No after 1 sec 78 service total count lower figure XXXX78 1 1 No after 1 sec 34 56 SET 0 3 1 0 0 31 00 x 4 SET 31 00 2 2 No after 1 sec 78 SET 0 0 0 SET 0 service total count 310000 set CHECK Flashing 0 1sec BUZZER PAD DISPLAY INDICATOR PHONE Door close CHECK CHECK No CHECK 82 68 CHECK user total count 2 SIGNAL SIGNAL DOUBLE 34 5...

Page 23: ...above step A KEY DISPLAY PAUSE 0 0 End of each 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 Flicker 0 1 sec BUZZER PAD DISPLAY INDICATOR PHONE CHECK No CHECK EXPRESS DEFROST 0 20 DEF A 0 B P 60 PL 0 15 A 0 B P 40 PL 5 pause time P 20 PL repeat CHECK Flicker 0 1 sec BUZZER PAD DISPLAY INDICATOR PHONE Door close CHECK CHECK...

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: ... arcing etc Carry out any remedial work that is necessary before operat ing the oven Do not operate the oven if any of the following conditions exist 1 Door does not 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 generat...

Page 26: ...itor 4 Disconnect the high voltage wire of the high voltage rectifier assembly and filament lead of the transformer from the magnetron 5 Remove the one 1 screw holding the airguide to the magnetron and remove the airguide 6 Remove the one 1 screw holding the insertion plate A to the mag netron and remove the insertion plate A 7 Remove the one 1 screw holding the chassis support to the mag netron 8...

Page 27: ...VAL 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 the wire leads from the fan motor 5 Remove the one 1 screw holding the capacitor holder to the oven cavity rear plate 6 Remove the one 1 screw holding the fan duct to the oven cavity rear plate 7 Release the tabs of the capacitor holder from fan d...

Page 28: ...te 5 Disconnect the wire leads of the power supply cord from the noise filter 6 Release the power supply cord from the oven cavity rear plate 7 Now the power supply cord is free 2 REINSTALL 1 Insert the moulding cord stopper of power supply cord into the square hole of the oven cavity rear plate referring to the Figure C 3b 2 Install the earth wire lead of power supply cord to the cavity rear plat...

Page 29: ...r of the monitor switch is pressed with the door closed 6 Secure the screws with washers firmly 7 Check the operation of all switches If each switch has not activated with the door closed loosen screw and adjust the latch hook posi tion 2 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 push...

Page 30: ... free NOTE At this moment the door badge is attached on the door case 2 REINSTALL OF THE DOOR 1 Reinstall all door parts except the choke cover 2 Catch two 2 pins of door panel on two 2 holes of upper and lower oven hinges 3 Insert the one 1 cushion ferrite into the lower opening between the door panel and the door frame 4 Reinstall choke cover to door panel by pushing NOTE After any service to th...

Page 31: ...enna holder on the tab of the oven cavity bottom plate Refer to Figure C 10 4 Insert the antenna holder into the hole of the oven cavity bottom plate and fit the hole of the antenna holder with an antenna motor shaft Refer to Figure C 10 5 Install the antenna holder to the oven cavity bottom plate with the one 1 screw and the one 1 washer Refer to Figure C 8 6 Install the antenna motor to the oven...

Page 32: ...n are attached to the four 4 edges of the ceramic shelf The one 1 rubber packing without a fin is the front edge of the ceramic shelf 5 Put the front edge of the ceramic shelf into the front edge of the oven cavity bottom plate 6 Push down the rear edge of the ceramic shelf into the oven cavity bottom plate 7 Now the ceramic shelf is installed WARNING Make sure that the rubber packing is not caugh...

Page 33: ...WER SUPPLY CORD NOISE FILTER FUSE COM WHT WHT RED WHT WHT N C N O COM CONNECTOR ORG ORG WHT BRN BLU ANTENNA MOTOR MONITOR SWITCH WHT GRY RED RED YLW YLW ORG YLW BLU BLU IC1 RY2 T1 RY3 CN G CN A 7 1 1 2 CN B 2 3 4 5 1 BLU GRY RY2 PRIMARY INTERLOCK RELAY CN A NEUTRAL HOT EARTH RED BLK GRN GRY N O COM DOOR SENSING SWITCH SECONDARY INTERLOCK SWITCH CONTROL UNIT 2 1 GRN G R N G R N GRY CN B NOTE Hot GR...

Page 34: ... P42 INTI INTO RESET P71 P70 XIN 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 XOUT VSS P26 P27 IC1 IZA897 R33 4 7K R31 15K ON DEF ON X2 C5 C6 J3 J6 J5 R5 4 7K CF1 CSTLS4M00G56P18 R50 R54 R58 R51 R52 R53 R55 R56 R57 100 X 9 LED 1 R40 2 7K SP1 Q2 DTA123ESA IC3 KD65004AP 47u 10V 0 1u 50V G12 G11 G10 G9 G1 G2 G3 G4 G5 G6 G7 G8 ...

Page 35: ...P11 P12 P13 P14 P15 P16 P17 P20 P21 P22 P23 P24 P25 XOUT VSS P26 P27 IC1 R31 15K ON DEF ON X2 C5 C6 R5 4 7K CF1 R50 R54 R58 R51 R52 R53 R55 R56 R57 100 X 9 R40 2 7K SP1 47u 10V 0 1u 50V G12 G11 G10 G9 G1 G2 G3 G4 G5 G6 G7 G8 R88 R87 R86 R85 R84 4 7K X 5 R83 5 6 DOUBLE QUANTITY 3 4 START 1 2 SET SIGNAL KEY UNIT 7 8 9 0 or CHECK STOP CLEAR EXPRESS DEFROST SELECTA TIME CN G R80 R81 R82 4 7K x4 CSTLS4...

Page 36: ...31 R 32 E Q60 C N G C N B MIC R O 1 MIC R O 2 C N D R 84 IC 1 J F J C J B C 10 R 102 C 100 D100 T B 2 J 7 D5 OL B B E E Q21 Q24 R 6 ZD3 S M T T M T B 1 R 100 Q23 J 9 D10 C 3 B E D21 D22 11 12 T 1 P P S V R S 1 V R S 2 P OWE R C N A P OWE R C 1 E B Q22 R 40 S P 1 10 C 62 B R 33 R 3 C 7 ZD2 2 3 6 5 7 J 4 J 3 4 R 67 IC 3 R 5 C 30 C 31 1 1 12 3 1 1 33 32 25 20 15 40 50 55 64 3 3 1 1 7 1 60 16 9 8 4 5 ...

Page 37: ...h the following information 1 MODEL NUMBER 2 REF NO 3 PART NO 4 DESCRIPTION Parts marked may cause undue microwave exposure Parts marked are used in voltage more than 250V PartsGuide 1 OVEN PARTS 2 DOOR AND CONTROL PANEL PARTS INDEX INSTRUCTION BOOK TOP PAD ASSEMBLY FPADBA385WRK0 BOTTOM PAD ASSEMBLY FPADBA386WRK0 WRAP COVER SSAKHA034WRE0 DOOR PROTECTION SHEET SPADPA204WRE0 PACKING CASE SPAKCE434WR...

Page 38: ... 7 7 4 30 4 24 4 24 2 4 4 10 6 1 2 1 4 14 4 20 7 1 4 8 2 3 7 8 7 12 4 11 1 14 1 2 4 29 4 20 4 22 4 34 7 3 4 25 7 3 7 1 1 4 6 3 6 6 1 12 1 4 4 24 4 36 7 1 7 9 7 8 7 2 1 7 7 7 1 6 2 4 4 17 4 39 2 2 4 13 4 12 4 31 7 11 7 12 7 10 4 26 4 26 4 2 4 19 4 23 4 40 4 21 4 21 4 21 4 1 7 6 7 13 7 13 7 13 4 9 4 32 4 18 4 16 1 10 1 9 4 28 6 5 x2 6 2 4 27 4 20 4 20 4 37 4 38 ...

Page 39: ... part 4 3 MLEVPA227WRF0 AF Latch switch lever A 4 4 MLEVPA228WRF0 AF Latch switch lever B 4 5 MLEVPA229WRF0 AF Latch switch lever C 4 6 MSPRCA108WRE0 AC Latch lever spring 4 7 MSPRTA191WRE0 AC Switch lever B spring 4 8 PHOK A160WRFZ AN Latch hook 4 9 FDUC A341WRY0 BL Steam duct sub assembly 4 10 PSKR A351WRP0 AY Steam guide 4 11 LBNDKA136WRP0 AQ HV capacitor holder 4 12 NFANJA029WRE0 AK Fan blade ...

Page 40: ...A038WRE0 AA Special screw 7 4 LX CZ0052WRE0 AA Special screw 7 5 LX EZA042WRE0 AB Special screw 7 6 XBPWW40P04000 AB Screw 4mm x 4mm 7 7 XHPS740P08000 AB Screw 4mm x 8mm 7 8 XHTS740P08000 AC Screw 4mm x 8mm 7 9 XHPS730P06000 AB Screw 3mm x 6mm 7 10 XHTS740P08RV0 AG Screw 4mm x 8mm 7 11 XOTS740P12000 AA Screw 4mm x 12mm 7 12 XOTS740P08000 AA Screw 4mm x 8mm 7 13 XOTWW40P10000 AA Screw 4mm x 10mm 1 ...

Page 41: ...ual wire harness may be different from illustration 5 1 6 5 2 5 4 5 1 4 5 6 8 6 7 5 1 15 5 1 7 5 1 8 5 1 8 5 1 9 5 1 13 5 1 17 5 1 11 5 1 3 5 1 4 1 5 1 1 5 1 4 5 5 1 12 5 1 12 5 1 14 5 1 18 5 1 4 5 1 17 5 1 2 5 1 16 5 1 16 5 1 16 5 1 16 x4 x2 6 9 5 3 5 1 5 1 5 5 1 10 5 1 4 3 5 1 4 4 5 1 4 2 ...

Page 42: ...1 LSTPPA180WRF0 AK Glass stopper R 5 1 4 2 LSTPPA182WRF0 AN Glass stopper U 5 1 4 3 PGLSPA516WRE0 AU Front door glass 5 1 4 4 PSLDMA198WREZ BB Sealer plate 5 1 4 5 XETS740P08000 AA Screw 4mm x 8mm 5 1 5 GWAKPA580WRM0 AQ Door handle 5 1 6 JHNDMA040WRW0 AN Handle lever 5 1 7 LANGKA874WRW0 AR Latch lever 5 1 8 LSTPPA181WRF0 AL Latch head 5 1 9 MSPRTA190WRE0 AD Latch spring 5 1 10 PCUSUA506WRP0 AC Cus...

Page 43: ...PCUSUA194WRP0 1 4 26 AC PCUSUA505WRP0 2 5 1 15 AC PCUSUA506WRP0 2 5 1 10 AC PCUSUA507WRP0 1 4 36 AC PCUSUA508WRP0 2 5 1 18 AC PCUSUA511WRP0 1 4 25 AC PCUSUA514WRP0 1 4 27 AB PCUSUA517WRP0 1 4 37 AE PCUSUA518WRP0 1 4 39 AC PDUC A888WRFZ 1 4 13 AM PDUC A966WRFZ 1 4 28 AT PFILWA060WRP0 1 4 29 AD PGLSPA516WRE0 2 5 1 4 3 AU PHOK A160WRFZ 1 4 8 AN PPACGA171WRE0 2 5 4 AK PSHEPA644WRE0 1 4 30 AD PSHEPA649...

Page 44: ...out prior written permission of the publisher COPYRIGHT XXXX BYSHARP CORPORATION ALL RIGHTS RESERVED COPYRIGHT 2006 BY SHARP CORPORATION ALL RIGHTS RESERVED No part of this publication may be reproduced stored in retrieval systems or transmitted in anyform or by any means electronic mechanical photocopying re cording or other wise without prior written permission of the publisher ...

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