R-21AT SERVICE MANUAL SX802R21ATPKK COMMERCIAL MICROWAVE OVEN 1000W/ R-21AT ON DEF NO. X2 CHECK MODEL R-21AT In interests of user-safety the oven should be restored to its original condition and only parts identical to those specified should be used. TABLE OF CONTENTS Page SERVICING ................................................................................................................. INSIDE FRONT COVER CAUTION, MICROWAVE RADIATION ...........................................................
R-21AT SERVICING WARNING TO SERVICE PERSONNEL Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with following parts will result in electrocution. High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier, High voltage fuse, High voltage harness. REMEMBER TO CHECK 3D 1) Disconnect the supply. 2) Door opened, and wedged open. 3) Discharge high voltage capacitor. WARNING: AGAINST THE CHARGE OF THE HIGH-VOLTAGE CAPACITOR.
R-21AT SERVICE MANUAL PRODUCT SPECIFICATIONS GENERAL INFORMATION COMMERCIAL MICROWAVE OVEN APPEARANCE VIEW R-21AT GENERAL IMPORTANT INFORMATION This Manual has been prepared to provide Sharp Corp. Service engineers with Operation and Service Information. It is recommended that service engineers carefully study the entire text of this manual, so they will be qualified to render satisfactory customer service.
R-21AT PRODUCT DESCRIPTION SPECIFICATION ITEM DESCRIPTION Power Requirements Power Output Case Dimensions Cooking Cavity Dimensions Control Complement Set Weight 230 - 240 Volts 50 Hertz Single phase, 3 wire earthed 1000 W nominal of RF microwave energy (measured by method of IEC 705) Operating frequency 2450 MHz Width 520 mm Height 309 mm including foot Depth 406 mm Width 351 mm Height 211 mm Depth 372 mm Touch Control System Timer (0 - 99 minutes and 99 seconds) Microwave Power for Variable Cookin
R-21AT APPEARANCE VIEW OVEN 10 1. Oven light 2. Ceramic shelf 3. Control panel 9 4. Cavity face plate 5. Door latch openings 6. Door latches 7. Door hinges 8. Door seals and sealing surfaces 9. Door handle 10.Oven door with see-through window 11.Air ventilation cover and openings 12.Power supply cord 13.Air intake openings 14.Outer case cabinet 7 1 12 11 2 13 14 6 8 4 5 3 TOUCH CONTROL PANEL 1. 2. 3. 4.
R-21AT OPERATION SEQUENCE OFF CONDITION 6-1. When the oven door is opened during or after the cycle of a cooking program, the 1st. interlock switch, latch switch and 2nd. interlock relay control switch must open their contacts first. After that the contacts (COM-NC) of the monitor switch can be closed. 6-2. When the oven door is closed, the contacts (COMNC) of the monitor switch must be opened. After that the contacts of the 1st. interlock switch, latch switch and 2nd.
R-21AT FUNCTION OF IMPORTANT COMPONENTS DOOR OPEN MECHANISM HIGH VOLTAGE FUSE 0.75A The door is opened by grasping the door handle, refer to Figure D-1. When the door handle is grasped, the handle lever is pulled. And then the upper and lower latch heads are moved upward by the handle lever, and they are released from the latch hook. Now the door will open. The high voltage fuse blows when the high voltage rectifier or the magnetron is shorted.
R-21AT TROUBLESHOOTING GUIDE Home fuse or circuit breaker blows when power cord is plugged into wall outlet. OFF CONDITION Fuse M10A blows when power cord is plugged into wall receptacle. . does not appear in display when power cord is first plugged into wall outlet. Oven lamp does not light when door is opened. Oven lamp lights but fan motor and antenna motor do not operate. COOKING CONDITION Oven does not go into cook cycle when START pad is touched.
R-21AT TEST PROCEDURES PROCEDURE LETTER A MAGNETRON TEST COMPONENT TEST NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL WHILE THE OVEN IS IN OPERATION. CARRY OUT 3D CHECKS. Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal. To test for an open circuit filament use an ohmmeter to make a continuity test between the magnetron filament terminals, the meter should show a reading of less than 1 ohm.
R-21AT TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST Initial temperature .................................................................................................. T1 = 11°C Temperature after (42 + 2) = 44 sec ...................................................................... T2 = 21°C Temperature difference Cold-Warm ...................................................................... ∆T1 = 10˚C Measured output power The equation is “P = 100 x ∆T” .........................................
R-21AT TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST it has been charged. D. A short-circuited capacitor shows continuity all the time. E. An open capacitor constantly shows a resistance about 10 MΩ because of its internal 10MΩ resistance. F. When the internal wire is opened in the high voltage capacitor shows an infinite resistance. G. The resistance across all the terminals and the chassis must be infinite when the capacitor is normal.
R-21AT TEST PROCEDURES PROCEDURE LETTER H NOISE FILTER TEST COMPONENT TEST L N MEASURING POINTS Between N and L Between terminal N and WHITE Between terminal L and RED INDICATION OF OHMMETER Approx. 680 kΩ Short circuit Short circuit If incorrect readings are absorbed, replace the noise filter unit. DISCHARGE RESISTOR 680 kΩ NOISE SUPPRESSION COIL LINE CROSS CAPACITOR 0.068µF/ AC 250V LINE BYPASS CAPACITOR 0.0033µF/ AC 250V CARRY OUT 4R CHECKS. I FUSE M10A NOISE FILTER CARRY OUT 3D CHECKS.
R-21AT TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST e) Wrong figure appears. f) A certain group of indicators do not light up. g) The figure of all digits flicker. 2-3 Other possible troubles caused by defective control unit. a) Buzzer does not sound or continues to sound. b) Clock does not operate properly. c) Cooking is not possible.
R-21AT TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST N PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD (PWB) IS OPEN To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit on the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given below for repair. Problem: POWER ON, indicator does not light up. CARRY OUT 3D CHECKS.
R-21AT TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL The touch control section consists of the following units as shown in the touch control panel circuit. (1) Control Unit (2) Key Unit 11) Relay Driving Circuit This is a circuit for driving output relay by IC1 output. 12) Door Sensing Switch Circuit This is a circuit for driving IC1 to detect door opening/ closing. The principal functions of these units and the signals communicated among them are explained below. 2.
R-21AT Pin No. Signal I/O Description 7-8 AN5-AN4 IN Terminal to change functions according to the model. Signal in accordance with the model in operation is applied to set up its function. 9-10 AN3-AN2 IN Terminal not used. 11 AN1 IN Input signal which communicates the door open/close information to LSI. Door closed; "L" level signal (0V). Door opened; "H" level signal (+5V). 12 AN0 IN Terminal not used. 13 P55 OUT Magnetron high-voltage circuit driving signal.
R-21AT Pin No. Signal I/O Description 27 RESET IN 28 P71 OUT 29 P70 IN/OUT 30 XIN IN 31 XOUT OUT 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, P34 will be input into P27. When no key is touched, the signal is held at "L" level. 34 P26 IN Signal similar to P27.
R-21AT 2-2 Memory IC (IC2) X24C02P is a 2K-bit, serial memory, enabling CMOS to be erased/written electrically. This memory is constructed with 256 registers x 8bits, enabling individual access, read and write operations to be performed. Details of input/output signal for IC2 are as shown in the following diagram.
R-21AT TOUCH CONTROL PANEL SERVICING 1. Precautions for Handling Electronic Components This unit uses CMOS LSI in the integral part of the circuits. When handling these parts, the following precautions should be strictly followed. CMOS LSI have extremely high impedance at its input and output terminals. For this reason, it is easily influenced by the surrounding high voltage power source, static electricity charge in clothes, etc. and sometimes it is not fully protected by the built-in protection circuit.
R-21AT 3) Practice for inputting total using times (Ex. 310000 times). ... Flashing / ... 0.1sec BUZZER PROCEDURE FOR CHECKING/CLEARING SERVICE COUNTS OF MICROWAVE OVEN The following procedure enables the servicer to obtain the total using times (cook cycles) since the microwave oven is purchased and the total operation time (hours) since the microwave oven is purchased. The maximum capacity of the total using is 999,999 times, and the maximum capacity of total operation time is 999,999 hours.
R-21AT 5) Practice for cancelling total using times and total operation time (user and service) and all other counter. ... Flashing / ... 0.1sec BUZZER PAD (Door close) SET SET (within 2.0sec.) DOUBLE QUANTITY CHECK SINGLE SET DISPLAY . . . . . . . . . KEY 0 DISPLAY 0 1 : 9 START INDICATOR PHONE 1 : 9 A 2) To check the constants of Express defrost. DOUBLE " " : Flicker / PAD CHECK EXPRESS DEFROST 1. EXPRESS DEFROST T = STG1 + STG 2 + STG3 STG = A x T + B 1) To set the constants of Express defrost.
R-21AT COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before operating the oven. 1. Disconnect the oven from power supply. 2. Visually check the door and cavity face plate for damage (dents, cracks, signs of arcing etc.). 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.
R-21AT 3. Remove the one (1) screw holding the air guide to the magnetron and remove the air guide. 4. Remove the one (1) screw holding the chassis support to the magnetron. 5. Carefully remove four (4) screws holding magnetron to waveguide, when removing the screws hold the magnetron to prevent it from falling. 6. Remove the magnetron from the waveguide with care so the magnetron antenna is not hit by any metal object around the antenna. CAUTION: WHEN REPLACING THE MAGNETRON, BE SURE THE R.F.
R-21AT FAN MOTOR REPLACEMENT CAUTION: * Do not reuse the removed fan blade because the hole (for shaft) may be larger than normal. 12.Remove the two (2) screws holding the fan motor to the fan duct. 13.Now, the fan motor is free. REMOVAL 1. CARRY OUT 3D CHECKS. 2. Remove the one (1) screw holding the noise filter to the chassis support. 3. Release the noise filter from the tab on the fan duct. 4. Disconnect the wire leads from the fan motor. 5.
R-21AT 1ST. INTERLOCK SWITCH, LATCH SWITCH, 2ND. INTERLOCK RELAY CONTROL SWITCH, AND MONITOR SWITCH REMOVAL 4. Make sure that the monitor switch is operating properly and check continuity of the monitor circuit. Refer to chapter "Test Procedure" and Adjustment procedure. 1. CARRY OUT 3D CHECKS. 2. Remove the control panel assembly referring to "CONTROL PANEL ASSEMBLY REMOVAL". 3. Disconnect the leads from all switches. 4. Remove the two (2) screws holding the latch hook to the oven cavity. 5.
R-21AT 5. Release choke cover from door panel. 6. Now choke cover is free. RE-INSTALL OF THE DOOR 1. Re-install 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. Re-install choke cover to door panel by pushing. Choke Cover NOTE: After any service to the door; (A) Make sure that door sensing switch and secondary interlock switch are operating properly. (Refer to chapter "Test Procedures".).
R-21AT INSTALLATION OF CERAMIC SHELF 1. Disconnect the oven from the power supply. 2. Open the oven door and wedge it open. 3. Make sure that the smooth surface of the ceramic shelf face up. 4. Make sure that the rubber packing without a fin of the ceramic shelf faces the front of the oven. NOTE: The three (3) rubber packings with the fins and the one (1) rubber packing without a fin are attached to the four (4) edges of the ceramic shelf.
N EARTH G-Y LIVE A5 26 2ND. INTERLOCK RLAY CONTROL SWITCH B2 B1 FAN MOTOR 1ST. INTERLOCK SWITCH Figure O-2 Oven Schematic-Cooking Condition LATCH SWITCH H.V. RECTIFIER CAPACITOR 1.07µF AC2400V A7 H.V. FUSE 0.75A MAGNETRON FAN MOTOR AM H.V. RECTIFIER CAPACITOR 1.07µF AC2400V H.V. FUSE 0.75A MONITOR SWITCH ANTENNA MOTOR OL FM L MAGNETRON HIGH VOLTAGE TRANSFORMER MONITOR RESISTOR 0.8/20W RY-2 RY-3 DISCHARGE RESISTOR 10MΩ LINE BYPASS CAPACITOR 0.
H 2 CN-G T1 IC1 CONTROL UNIT 2 1 1 RY3 RY2 PNK PNK YLW ORG YLW YLW BLK G 7 5 WHT 4 3 2 1 PNK CN-A 2 GRY 1 GRN CN-B 3 27 4 WHT 5 WHT WHT GRY N.O. GRN GRY RED WHT E YLW Figure S-1. Pictrorial Diagram WHT ANTENNA MOTOR THERMAL CUT-OUT 125˚C(OVEN) BRN OVEN LAMP AND SOCKET ORG BLACK MARK BLK WHT N L BRN EARTH G-Y WHT WHT RED RED WHT RED ORG ORG ORG BRN PNK NEUTRAL FAN MOTOR MONITOR RESISTOR THERMAL CUT-OUT 145°C(MAG.) POWER TRANSFORMER H.V.
HIGH VOLTAGE TRANSFORMER OVEN LAMP ANTENNA MOTOR FAN MOTOR TARNTABLE MOTOR AC230-240V 50Hz COM N.O. COM N.O. A7 (J1) b c a d R90 100 1w 10G471K RY2 RY3 Q24 2SC1740S C10 470µ /25v – + JA R6 1k HZ20-1 ZD3 28 D23 Q22 DTD143ES C13 10µ/25v – + 4 D70 R71 4.7k IC2 A0 1 8 VCC A1 TEST SCL A2 VSS 4 5 SDA X24C02P Q21 DTC143ES R30 100 C20 0.1µ/50v R32 2.7k + 5 C7 CF1 CST4.
R-21AT 1 2 4 3 5 6 A A 1 13 DIP F R33 R32 R3 C7 3 1 2 16 ZD2 Q2 1 (CN - D) IC3 15 (4) 5 6 (J3) (J4) 7 60 64 3 SP1 (JA) (Q23) D22 MICRO 2 (R1) Q1 E (ZD1) (R2) (R101) B C1 11 (15) (16) E Q3 C2 C9 (TB1) F (CT1) (17) 1 8 7 (J1) P VRS1 S P 12 T1 1 (C12) (RY1) (D20) C20 C21 B CN - A D3 D4 D2 D1 B (C10) (D5) OL SM TTM (VRS2) POWER POWER (J2) 6 4 (ZD3) (R6) (Q24) E E H F G 13 (D6) Q21 B Q20 E (C13) DANGER-CERTAIN PART IS INTENTIONALLY NOT GROU
R-21AT PARTS LIST Note: The parts marked "∆" may cause undue microwave exposure. The parts marked "*" are used in voltage more than 250V. REF. NO. PART NO.
R-21AT Note: The parts marked "∆" may cause undue microwave exposure. The parts marked "*" are used in voltage more than 250V. REF. NO. R90 RY2 RY3 SP1 T1 VRS1 ZD2 ZD3 3- 2 3- 2-1 3- 2-2 3- 2-3 3- 3 PART NO.
R-21AT Note: The parts marked "∆" may cause undue microwave exposure. The parts marked "*" are used in voltage more than 250V. REF. NO. PART NO.
R-21AT 2 1 4 3 6 5 OVEN AND CABINET PARTS 7-3 A A 7-3 2-1 7-3 1-10 1-9 4-23 B 7-13 7-3 B 4-9 4-10 7-13 7-6 4-21 1-4 7-12 C 7-13 7-1 4-26 4-17 6-4 1-13 4-26 C 4-27 4-35 1-4 4-28 1-17 4-14 7-1 7-10 D 1-18 1-8 4-15 4-2 7-10 7-9 7-3 4-25 D 7-11 1-12 4-18 7-10 4-36 7-1 E 4-6 7-1 E 4-20 6-7 4-19 7-1 7-4 1-7 1-15 4-3 1-11 1-3 1-1 4-8 7-2 4-13 7-4 6-2 4-1 4-34 7-7 4-22 7-1 1-6 4-7 7-14 4-37 F 4-12 4-4 F 4-6 2-2 1-2 4-33 4-5 1-5 1-3 6-3
R-21AT 2 1 4 3 6 5 3-1 CONTROL PANEL PARTS A A 3-3 3-2 3-3 3-2-3 3-3 B B 3-2-2 3-3 6-5 C C DOOR PARTS 3-2-1 5-15 5-21 D 5-17 5-16 D 5-13 5-2 5-16 5-20 5-4-2 E 5-16 5-13 5-4-4 E x4 5-4 5-1 5-4-1 5-4-3 5-4-4 x2 5-16 5-12 5-14 F F 5-8 5-7 5-19 5-9 5-18 5-12 5-11 5-3 5-8 5-19 G G 5-6 5-5 MISCELLANEOUS 5-10 6-2 H H Actual wire harness may be different from illustration. 1 2 4 3 5 6 '98SHARP CORP. (11S0.520E) Printed in Japan.
