R-880B SERVICE MANUAL S9839R880BPM/ DOUBLE GRILL CONVECTION MICROWAVE OVEN COOK HELP Info Display MULTI COOK REHEAT SENSOR HELP Fresh Vegetables Frozen Vegetables MIX EASY DEFPST ACTION Reheat Pie Jacket Potato Rice Pasta R-880B GRILL CONVEC REHEAT POWER MIXLEVEL LESS DOUBLE GR MODEL CONVENIENCE /PIZZA SENSOR INSTANT MORE ILL CONVEC TIO 1 2 3 4 5 6 7 8 9 0 N 40˚ C 70˚ C 130˚ C 150˚ C 160˚ C 180˚ C 200˚ C 220˚ C 230˚ C 250˚ C STOP CLEAR Sensor CLOCK INSTANT COOK START In
R-880B
R-880B SERVICE MANUAL PRODUCT SPECIFICATIONS GENERAL INFORMATION DOUBLE GRILL CONVECTION MICROWAVE OVEN APPEARANCE VIEW R-880B GENERAL IMPORTANT INFORMATION This Manual has been prepared to provide Sharp Corp. Service engineers with Operation and Service Information. OPERATING SEQUENCE 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-880B PRODUCT DESCRIPTION SPECIFICATION ITEM DESCRIPTION Power Requirements Power Consumption Power Output Grill heater Power Output (Top heater) Bottom heater Power Output Case Dimensions Cooking Cavity Dimensions Turntable diameter Control Complement 220 Volts 50 Hertz Single phase, 3 wire earthed Microwave cooking 1.6 kW Top Heater mode 1.3 kW Grill cooking Bottom heater mode 0.9 kW Top and Bottom heater mode 2.1 kW Convection cooking 2.
R-880B APPEARANCE VIEW OVEN 1. Oven lamp 2. Top heaters (Grill heaters) 3. See through door 4. Door hinges 5. Door safety latches 6. Door seals and sealing surfaces 7. Bottom heater 8. Oven cavity 9. Turntable motor shaft 10.Ventilation openings 11.Waveguide cover 12.Door opening button Turntable 13.Control panel support 14.Digital display 15.Power supply cord 16.Outer cabinet 17.Menu label Bottom heater 4 2 u 0 t r 0 1 5 8 9 e q y 3 6 0 High rack 7 5 0 w NOTE: 1.
R-880B OPERATION SEQUENCE OFF CONDITION Closing the door activates the 1st. latch switch and 2nd. interlock relay control switch. IMPORTANT: When the oven door is closed, the contacts COM-NC of the monitor switch must be open. When the microwave oven is plugged in a wall outlet (220V 50Hz), the line voltage is supplied to the noise filter and the control unit. Contact 1st. latch switch 2nd.
R-880B 1. The relay RY3 + RY5 + RY6 are energized. 2. The numbers of the digital read-out start the count down to zero. 3. Then the top heaters, turntable motor, oven lamp and fan motor are energized. 4. Now, the food is grilled by the top heaters. 5. Upon completion of the selected cooking time, audible signal sounds and the contacts of relays RY3 + RY6 are opened, then the top heaters, turntable motor and oven lamp are de-energized. But the relay RY5 stays closed and the fan motor operates for 5 minutes.
R-880B energized. 4. The relay RY2 + RY4 are energized alternately within a 48 seconds time base by the control unit. 5. The bottom heater operate through the relay RY4 is energized. And the high voltage transformer operates through the relay RY2 is energized. 6. The relationship between the top heating elements and magnetron operations are as follows. 26 SEC. NOTE: 1. In case of Automatic operations, the limitations of power output are not carried out. 2.
R-880B Selected Temperature (˚C) Top Heaters Power (%) 3. Sensor detects moisture and humidity and calculates cooking time and variable power. Bottom Heater Power (%) 250 40 40 230 220 200 40 40 30 40 40 70 180 160 20 10 70 70 150 130 70 10 10 10 70 60 40 40 10 30 AH SENSOR COOKING SEQUENCE 1.
R-880B judgment that there is a fire in the oven cavity and will switch off the relays to the power transformer, fan motor, turntable motor and the oven lamp. The LSI also stops counting down. 3. Once the fire sensor feature has shut the unit down, the programmed cooking cycle may be resumed by pressing the "START" pad or the unit may be reset by pressing the "CLEAR" pad.
R-880B ASYMMETRIC RECTIFIER FAN MOTOR The asymmetric rectifier is a solid state device that prevents current flow in both directions. And it prevents the temperature rise of the high voltage transformer by blowing the fuse M10A when the high voltage rectifier is shorted. The fan motor drives a blade which draws external cool air. This cool air is directed through the air vanes surrounding the magnetron and cools the magnetron.
R-880B 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 assembly, High voltage harness. REMEMBER TO CHECK 3D REMEMBER TO CHECK 4R 1) Disconnect the supply. 2) Door opened, and wedged open. 3) Discharge high voltage capacitor. 1) Reconnect all leads removed from components during testing.
11 AH. SENSOR CONVECTION COOKING CONDITION MIX COOKING CONDITION GRILL COOKING CONDITION MICROWAVE COOKING CONDITION COOKING CONDITION (COMMON MODE) OFF CONDITION CONDITION Oven is in sensor cooking condition but AH sensor does not end 1st. stage or does not stop cooking cycle or the oven stops soon. Oven stops after 4 minutes 15 sec.. Convection motor does not operate. Temperature is lower or higher than preset. Bottom heater does not operate. Top heaters do not operate.
R-880B 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-880B TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST Initial temperature .................................................................................................. T1 = 11°C Temperature after (47 + 2) = 49 sec ...................................................................... T2 = 21°C Temperature difference Cold-Warm ....................................................................... ∆T1 = 10C Measured output power The equation is “P = 90 x ∆T” ..........................................
R-880B TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST NOTE: FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER, THE BATTERIES OF THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE AT LEAST 6 VOLTS, BECAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE SHOWN IN BOTH DIRECTIONS. D HIGH VOLTAGE CAPACITOR TEST CARRY OUT 3D CHECKS. A. Isolate the high voltage capacitor from the circuit. B. Continuity check must be carried out with measuring instrument which is set to the highest resistance range. C.
R-880B TEST PROCEDURES PROCEDURE LETTER G BLOWN FUSE M10A COMPONENT TEST CARRY OUT 3D CHECKS. If the fuse M10A is blown when the door is opened, check the 1st. latch switch, 2nd. interlock relay, monitor switch and monitor resistor. If the fuse M10A is blown, there could be a short or ground in electrical parts or wire harness. Check them and replace the defective parts or repair the wire harness.
R-880B TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST Check the resistance across the terminals of the heater as described in the following table. Table: Resistance of heater Parts name Resistance Top heaters Approximately 20 Ω x 2 = 40 Ω Bottom heater Approximately 61 Ω 2. Insulation resistance. Disconnect the wire leads to the heater to be tested. Check the insulation resistance between the heater terminal and cavity using a 500V - 100MΩ insulation tester.
R-880B TEST PROCEDURES PROCEDURE LETTER N KEY UNIT TEST COMPONENT TEST If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is marking good contact, verify that the door sensing switch (stop switch) operates properly; that is the contacts are closed when the door is closed and open when the door is open.
R-880B TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST STEPS OCCURRENCE 1 The rated AC voltage is not present at Power terminal of CPU connector (CN-A). Check supply voltage and oven power cord. CAUSE OR CORRECTION 2 The rated AC voltage is present at primary side of low voltage transformer. Low voltage transformer or secondary circuit defective. Check and repair. 3 Only pattern at "a" is broken. *Insert jumper wire J1 and solder. (CARRY OUT 3D CHECKS BEFORE REPAIR.
R-880B TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNIT To determine if the sensor is defective, the simplest method is to replace it with a new replacement sensor. (1) Disconnect oven from power supply and then remove outer case. (2) Discharge the high voltage capacitor. (3) Remove the AH sensor. (4) Install the new AH sensor. (5) Re-install the outer case.
R-880B 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. 4) ACL A circuit to generate a signal which resets the LSI to the initial state when power is supplied. (1) Key Unit (2) Control Unit (The Control unit consists of Power unit and CPU unit.) 5) Buzzer Circuit The buzzer is responsive to signals from the LSI to emit audible sounds (key touch sound and completion sound).
R-880B Pin No. 8 Signal AN2 I/O IN Description Input signal which communicates the door open/close information to LSI. Door closed; "H" level signal. Door opened; "L" level signal. AH sensor input. This input is an analog input terminal from the AH sensor circuit, and connected to the A/D converter built into the LSI.
R-880B Pin No. Signal I/O Description 29 P75 OUT Key strobe signal. Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G4 line key on matrix is touched. 30 P74 OUT 31 P73 OUT Key strobe signal. Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G3 line key on matrix is touched. Key strobe signal. Signal applied to touch-key section.
R-880B Pin No. 42 43 Signal P26 P25 I/O OUT OUT Description Convection motor driving signal. To turn on and off shut-off relay(RY1). "L" level during CONVECTION; "H" level otherwise. (Relay RY1 does not turn on at preheating mode.) Fan motor driving signal. To turn on and off the fan motor relay RY5. "L" level during cooking, or for 5 minutes after grill cooking or Mix cooking for a while after convection. "H" level otherwise. OFF ON 44 P24 OUT Terminal not used.
R-880B Pin No. 98-99 Signal I/O VL3-VL2 IN C2 IN 100 Description Power source voltage input terminal. Standard voltage for LCD. Terminal not used. ABSOLUTE HUMIDITY SENSOR CIRCUIT With this voltage given, the switches SW1 to SW5 in the LSI are turned on in such a way as to change the resistance values in parallel with R107 ~ R111 of IC2. 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.
R-880B SERVICING 1. Precautions for Handling Electronic Components 5) Re-connect the power supply cord after the outer case is installed. 6) Run the oven and check all functions. 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.
R-880B 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. 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.
R-880B CAUTION: WHEN REPLACING HIGH VOLTAGE RECTIFIER ASSEMBLY, ENSURE THAT THE CATHODE (EARTH) CONNECTION IS SECURELY FIXED TO THE CAPACITOR HOLDER AND BASE PLATE WITH AN EARTHING SCREW. 5. 6. 7. 8. Release the capacitor holder from the fan duct. Remove the capacitor from the capacitor holder. Now, the capacitor should be free. Release H.V. wire A from the high voltage rectifier assembly. 9. Now, the high voltage rectifier assembly should be free. HIGH VOLTAGE TRANSFORMER REMOVAL age transformer. 5.
R-880B THERMISTOR REMOVAL 1. CARRY OUT 3D CHECKS. 2. Now, the back plate with the sub back plate should be removed. 3. Disconnect the connector CN-D from the control unit. 4. Remove the one (1) screw holding the air duct to the oven cavity rear plate. 5. Remove the air duct assembly from the oven cavity rear plate. 6. Remove the one (1) screw holding the thermistor angle to the oven cavity rear plate. 7. Remove the thermistor angle together with thermistor from the oven. 8.
R-880B • Make sure that the axis of the shaft is not slanted. 3. Install the fan duct to the oven cavity rear plate with the one (1) screw. 4. Insert the tabs of the capacitor holder to the fan duct. 5. Install the capacitor holder to the oven cavity rear plate with the one (1) screw. 6. Install the noise filter to the fan duct and the chassis support with the one (1) screw. 7. Re-connect the wire leads to the fan motor.
R-880B Oven Cavity Back Plate Screw Power Supply Cord Screw Brown Wire Plug Body Bule Wire Green/Yelow Wire Plug Cover L N Chassis Support WHT RED T1 T2 Noise Filter Figure C-2(a). AC Plug Figure C-2(c). Wiring to Noise filter Screw Brown Wire Lead L Screw Moulding Cord Stopper Power Supplu Cord N Power Supply Cord Oven Cavity Rear Plate Green/Yelow Wire Lead Screw Blue Wire Lead Square Hole Figure C-2(b). AC Plug Wiring Figure C-2(d).
R-880B 1ST. LATCH SWITCH, 2ND. INTERLOCK RELAY CONTROL SWITCH AND MONITOR SWITCH ADJUSTMENT If the 1st. latch switch, 2nd. interlock relay control switch and monitor switch do not operate properly due to a misadjustment, the following adjustment should be made. 1. CARRY OUT 3D CHECKS. 2. Loosen the two (2) screws holding the latch hook to the oven cavity front flange. 3. With the door closed, adjust the latch hook by moving it back and forward or up and down.
R-880B screws. 6. Catch two (2) pins of door panel on two (2) hole of upper and lower oven hinges. 7. Re-install choke cover to door panel by pushing. Note: After any service to the door; (A) Make sure that door sensing switch and primary latch switch are operating properly. (Refer to chapter "Test Procedures".). (B) An approved microwave survey meter should be used to assure compliance with proper microwave radiation emission limitation standards. (Refer to Microwave Measurement Procedure.
R-880B MICROWAVE MEASUREMENT After adjustment of door latch switches, monitor switch and door are completed individually or collectively, the following leakage test must be performed with a survey instrument and it must be confirmed that the result meets the requirements of the performance standard for microwave oven. 2. 3. REQUIREMENT The safety switch must prevent microwave radiation emission in excess of 5mW/cm2 at any point 5cm or more from external surface of the oven. PREPARATION FOR TESTING: 4.
THERMAL CUT-OUT(OVEN) 34 RY4 COM. 1ST. LATCH SWITCH Figure O-2 Oven Schematic-Microwave cooking Condition H.V. RECTIFIER MAGNETRON T2 FM H.V. RECTIFIER CAPACITOR 1.07µF AC2200V MONITOR SWITCH GRILL HEATER (TOP) N.O. N.O. COM. MONITOR RESISTOR 0.8/ 20W N.O. MAGNETRON HIGH VOLTAGE TRANSFORMER RY4 COM. RY2 RY6 RY5 RY1 RY3 A3 A5 D3 D1 COM. COM. N.O. BOTTOM HEATER TURNTABLE MOTOR TTM OVEN LAMP ASYMMETRIC RECTIFIER 1ST. LATCH SWITCH CAPACITOR 1.
THERMAL CUT-OUT(OVEN) 35 RY4 COM. 1ST. LATCH SWITCH Figure O-3(b) Oven Schematic-Grill cooking Condition (BOTTOM HEATER mode) H.V. RECTIFIER MONITOR RESISTOR 0.8/ 20W MAGNETRON T2 FM CM H.V. RECTIFIER CAPACITOR 1.07µF AC2200V MONITOR SWITCH GRILL HEATER (TOP) N.O. N.O. COM. MONITOR RESISTOR 0.8/ 20W N.O. MAGNETRON HIGH VOLTAGE TRANSFORMER RY4 COM. RY2 RY6 RY5 RY1 RY3 A3 A5 D3 D1 COM. COM. N.O. BOTTOM HEATER TURNTABLE MOTOR TTM OVEN LAMP ASYMMETRIC RECTIFIER 1ST.
THERMAL CUT-OUT(OVEN) 36 RY4 COM. 1ST. LATCH SWITCH Figure O-4 Oven Schematic-Convection cooking Condition H.V. RECTIFIER MAGNETRON T2 FM H.V. RECTIFIER CAPACITOR 1.07µF AC2200V MONITOR SWITCH GRILL HEATER (TOP) N.O. N.O. COM. MONITOR RESISTOR 0.8/ 20W N.O. MAGNETRON HIGH VOLTAGE TRANSFORMER RY4 COM. RY2 RY6 RY5 RY1 RY3 A3 A5 D3 D1 COM. COM. N.O. BOTTOM HEATER TURNTABLE MOTOR TTM OVEN LAMP ASYMMETRIC RECTIFIER 1ST. LATCH SWITCH CAPACITOR 1.
THERMAL CUT-OUT(OVEN) 1ST. LATCH SWITCH 37 RY4 COM. H.V. RECTIFIER MONITOR RESISTOR 0.8/ 20W MAGNETRON T2 FM CM H.V. RECTIFIER CAPACITOR 1.07µF AC2200V MONITOR SWITCH GRILL HEATER (TOP) N.O. N.O. COM. MONITOR RESISTOR 0.8/ 20W N.O. MAGNETRON HIGH VOLTAGE TRANSFORMER RY4 COM. RY2 RY6 RY5 RY1 RY3 A3 A5 D3 D1 COM. COM. N.O. BOTTOM HEATER TURNTABLE MOTOR TTM OVEN LAMP ASYMMETRIC RECTIFIER 1ST. LATCH SWITCH CAPACITOR 1.07µF AC2200V MONITOR SWITCH N.O.
1 2 3 38 4 RY2 1 CN-A RY5 RY1 T1 5 ORG BRN BLK 5 RY6 5 RED CN-A 1 GRY 2 3 ORG 4 BRN ORG ORG COM 1ST. LATCH SWITCH COM. GRY H 6 WHT TURNTABLE MOTOR BLK WHT RED OVEN LAMP (HALOGEN LAMP) BOTTOM HEATING ELEMENT CONNECTOR WHT RED WHT EARTH L BRN RED WHT WHT NOISE FILTER M10A GRY GRY FAN MOTOR ORG GRY RED RED BRN THERMAL CUT-OUT 125°C(MG) WHT RED CONVECTION MOTOR RED WHT HIGH VOLTAGE TRANSFORMER H.V. CAPACITOR ASYMMETRIC RECTIFIER H.V. RECTIFIER H.V.
R-880B 2 1 4 3 6 5 A A Q2 2SB1238 R4 27 C10 D1-4 11ES1 2SB1238 c R2 680 1/2w + – C2 GND C3 VC C1 VA C9 VR C4 INT C5 BUZZER C15 FAN MOTOR C16 CONVECTION MOTOR C6 OVEN LAMP TURNTABLE MOTOR C14 BOTTOM HEATER C8 TOP HEATER C11 N.C. C7 MICRO C17 OVEN THERMISTOR C13 N.C. C12 DOOR SWITCH C4 10µ/35v Q1 C3 0.1µ/50v HZ16-1 ZD1 D2 R1 2.4k D4 b (J1) C B + 6 d 1 a LED R5 4.7k D1 D3 – 4 D6 C2 1000µ/35v 8 A1 10G471K AC220V 50Hz VRS1 B D5 C1 0.
C3 C5 C1 C10 C9 C15 C16 VC BUZZER VA LED VR FAN MOTOR CONVECTION MOTOR 4 C7 MICRO 5 OVEN C17 THERMISTOR C13 D30 D23 D22 G C12 C11 C14 BOTTOM HEATER DOOR SWITCH C8 TOP HEATER C6 C2 OVEN LAMP TURNTABLE MOTOR C4 GND C11 0.1µ/50v + – Q20 DTA123JKA Q21 DTA123JKA C21 0.1µ/50v Q22 DTA123JKA Q23 DTA143EKA Q24 DTA143EKA Q25 DTA143EKA LD10 LD9 LD8 LD7 LD6 IC2 BA4558 F2 F3 1.8kF R101 IC2 0.015µ/25v C102 (J11) (J12) R103 10k C104 C103 (J10) (J15) 4.
R-880B 2 1 4 3 6 5 A A DIP R3 CN - C 18 B 1 1 2 D6 CN - D 3 Q1 B 3 D5 1 C CN - B 4 D11 RY6 1 AC R1 E R2 C2 C 2 ZD1 C5 E Q3 SP1 D1 D3 C1 RY3 T-H D B R4 E Q2 R5 B D8 C3 C4 R6 D9 D10 B D 1 D2 8 RY4 B-H D4 E E 6 RY2 MICRO S P 4 VRS1 F F T1 5 (J1) FAN 1 5 CON AC D7 CN - A 6 LOT NO. G D12 RY1 G RY5 F H H Figure S-4.
R-880B 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-880B REF. NO. PART NO.
R-880B REF. NO. 7- 3 7- 4 7- 5 7- 6 7- 7 7- 8 7- 9 7-10 7-11 7-12 7-13 7-14 7-15 7-16 7-17 PART NO.
R-880B 2 1 4 3 6 5 OVEN AND CABINET PARTS A A 2-2 7-9 6-11 7-8 4-45 7-9 4-33 2-1 B B 7-10 4-25 7-12 4-23 1-23 4-29 4-26 7-9 7-10 7-5 6-14 7-10 6-14 7-7 1-8 4-4 4-37 4-42 1-11 7-7 C 4-15 1-14 7-4 1-20 1-12 4-30 1-16 4-31 4-34 4-27 7-15 7-13 4-3 7-10 7-10 4-40 4-43 4-32 1-8 4-18 7-13 4-24 D 1-22 1-21 7-1 4-19 7-10 C 7-17 6-5 D 4-39 7-8 4-1 4-41 1-9 1-15 7-1 7-8 1-17 7-7 7-6 4-44 4-36 1-10 7-6 4-35 7-10 1-13 4-14 7-6 4-16 6-7 7-1 7-1 E 7-6 4-
R-880B 2 1 4 3 6 5 3-6 CONTROL PANEL PARTS 3-4 A A 3-5 3-2 3-3 3-6 B B 3-3-3 6-12 3-1 C C DOOR PARTS 3-3-1 D 5-8 3-3-2 D 5-9 5-1 E E 5-6 5-2 5-7 F F 5-3 5-4 MISCELLANEOUS 5-5 G G 6-1 6-8 6-7 6-2 Actual wire harness may be different than illustration. 6-10 H H 6-9 1 2 4 3 5 6 '98SHARP CORP. (9K0.
