R-890SLM SERVICE MANUAL S3905R890PKS MICROWAVE OVEN WITH GRILL AND CONVECTION MODELS R-890SLM In interests of user-safety the oven should be restored to its original condition and only parts identical to those specified should be used. CONTENTS CHAPTER 1. BEFORE SERVICING CHAPTER 9. CONTROL PANEL ASSEMBLY CHAPTER 2. WARNING TO SERVICE PERSONNEL CHAPTER 10. PRECAUTIONS FOR USING LEAD-FREE SOLDER CHAPTER 3. PRODUCT SPECIFICATIONS CHAPTER 4. APPEARANCE VIEW CHAPTER 11.
CONTENTS CHAPTER 1. BEFORE SERVICING CHAPTER 2. WARNING TO SERVICE PERSONNEL CHAPTER 3. PRODUCT SPECIFICATIONS [1] SPECIFICATION .........................................3-1 CHAPTER 4. APPEARANCE VIEW CHAPTER 5. OPERATION SEQUENCE [1] OFF CONDITION ........................................5-1 [2] MICROWAVE COOKING CONDITION .......5-1 [3] GRILL COOKING CONDITION ...................5-2 [4] CONVECTION COOKING CONDITION .....5-2 [5] COMBI COOKING CONDITION..................5-2 [6] ON/OFF TIME RATIO ............
R-890SLM CHAPTER 1. BEFORE SERVICING [1] 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-890SLM CHAPTER 2. WARNING TO SERVICE PERSONNEL Microwave ovens contain circuitry capable of producing very high voltage and current, contact with any part of the high voltage circuit will result in electrocution. High voltage capacitor, Power transformer, Magnetron, High voltage rectifier assembly, High voltage fuse, High voltage harness. REMEMBER TO CHECK 3D REMEMBER TO CHECK 4R 1) Disconnect the supply. 1) Reconnect all leads removed from components during testing. 2) Door opened, and wedged open.
R-890SLM CHAPTER 3. PRODUCT SPECIFICATIONS [1] SPECIFICATION ITEM Power Requirements Power Consumption Power Output DESCRIPTION 230 - 240 Volts / 50 Hertz / Single phase, 3 wire earthed Microwave cooking 1.50 kW Approx. 6.5A Convection cooking 1.91 kW Approx. 8.0 A Top Grill mode ---------------------- 1.25kW Approx. 5.2A Grill cooking Bottom Grill mode ----------------- 0.70kW Approx. 2.9A Top and Bottom mode ------------ 1.90kW Approx. 7.9A Micro and Top Grill ---------------- 2.70kW Approx. 11.
R-890SLM CHAPTER 4. APPEARANCE VIEW [1] OVEN 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.
R-890SLM CHAPTER 5. OPERATION SEQUENCE [1] OFF CONDITION SWITCH Closing the door activates the monitored latch switch and the stop 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 (230 - 240V / 50Hz), the line voltage is supplied to the noise filter. Figure O-1 on page 13-1 1. The control unit is not energized. The display shows nothing (Fig. O-1 (a)). 2. Open the door.
R-890SLM [3] GRILL COOKING CONDITION 1. TOP GRILL (Figure O-3) 2. CONVECTION COOKING (Figure O-4) In this condition the food is cooked by the top grill heating element. Press GRILL button. And enter the cooking time by rotate ENCODER dial. When the START button is pressed, the following operation occur: When the pre-heat temperature is reached, a beep signal will sound indicating that the holding the temperature has been reached in the oven cavity. Open the door and place the food to cooked in the oven.
R-890SLM [6] ON/OFF TIME RATIO 3. MICROWAVE AND BOTTOM GRILL (Figure O-5c) Press MIX button 3 times. And enter the desired cooking time by rotating the ENCODER dial. And press MICRO POWER button to set the desired microwave power. When the INSTANT COOK/START button is touched, the following operations occur: In grill cooking, convection cooking or combi cooking, the top heater, bottom heater or magnetron operate within a 54 second time base.
R-890SLM 3. COOLING FAN OPERATION OPERATION MODE PREHEAT CONV. (OVEN) Others DEVICE Cooling Cooling fan Cooling fan Cooling fan After cooking Indication POWER CONTROL 60% 60% 60 min. then 100% 100% A cooling fan continues the rotation when Oven temperature is more than 120°C. Then, it stops when it is less than 105°C NOW COOLING is indicated during the cooling fan movement after operation is finished. (It isn’t indicated during a fan movement to stop on the way.) 4. CONVECTION POWER SETTING 4.1.
R-890SLM CHAPTER 6. FUNCTION OF IMPORTANT COMPONENTS [1] DOOR OPEN MECHANISM The door can be opened by pulling the door handle. When the handle is pulled, the latch head is pulled, the latch head is moved upward, and released from the latch hook now the door can be opened. CAUTION: BEFORE REPLACING A BLOWN FUSE F8A, TEST THE MONITORED LATCH SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER “TEST PROCEDURE”). [3] FUSE Door 1.
R-890SLM rised above 120°C, the fan motor remains rotating. Automatically the fan motor will be shut down at low temperature (less than 105°C). 2. The peak reverse voltage of D2 of the rectifier goes beyond the rated peak reverse voltage 1.7 KV in the voltage doubler circuit. Door 3. D2 of the rectifier is shorted. Oven Cavity 4. The large electric currents flow through the high voltage winding of the high voltage transformer. Grill Heating Element Convection Passage 5.
R-890SLM CHAPTER 7. TROUBLESHOOTING GUIDE When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which will be found in the “Test Procedure” section.
Service_R-890SLM.indd 14 COMBI COOKING CONDITION (MICRO./GRILL) COMBI COOKING CONDITION (MICRO./CONV.) COMBI COOKING CONDITION (COMMON MODE) GRILL COOKING CONDITION CONVECTION COOKING CONDITION MICROWAVE COOKING CONDITION COOKING CONDITION (COMMON MODE) OFF CONDITION CONDITION Top or Bottom Grill heating element does not heat. Oven goes into cook cycle but shuts down before end of cooking cycle. Oven seems to be operating but little or no heat is produced in oven load.
R-890SLM CHAPTER 8. TEST PROCEDURES [1] A: MAGNETRON 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-890SLM [3] C: HIGH VOLTAGE RECTIFIER TEST CARRY OUT 3D CHECKS. Isolate the high voltage rectifier assembly from the HV circuit. The high voltage rectifier can be tested using an ohmmeter set to its highest range. Connect the ohmmeter across the terminal B+C of the high voltage rectifier and note the reading obtained. Reverse the meter leads and note this second reading. The normal resistance is infinite in one direction and more than 100 kΩ in the other direction. CARRY OUT 4R CHECKS.
R-890SLM [7] G: THERMAL CUT-OUT TEST CARRY OUT 3D CHECKS. Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make a continuity test across the two terminals as described in the below. Parts Name Thermal cut-out 125°C Thermal cut-out 145°C Table: Thermal Cut-out Test Indication of ohmmeter (When Temperature of “ON” condition Temperature of “OFF” condition room temperature is approx. 20°C.) (closed circuit). (open circuit). This is not resetable type.
R-890SLM [12] L: GRILL HEATING ELEMENTS (TOP) AND BOTTOM HEATING ELEMENT TEST CARRY OUT 3D CHECKS. Before carrying out the following tests make sure the heating element is cool completely. 1. Resistance of heater. Disconnect the wire leads to the heating element to be tested. Using ohmmeter with low resistance range. Check the resistance across the terminals of the heating element as described in the following table.
R-890SLM WH3- 2 WH 3- 3 E XP R E S S C OOK C ONB I A UT O C OOK S T AR T INF O SW14 G R IL L SHORT CUTS SW9 SW15 SW13 KITCHEN TIMER / CLOCK SET SW11 SW6 E NT E R SW3 QUIC K &E A SY MIC R O P OWE R SW10 AUT O MINUT E WH3-8 S T OP / C L E AR SW4 WH3-9 SW1 WH3-7 WH3- 4 WH3- 1 SW8 C O NV .( ? ) SW12 SW7 SW5 E XP R E S S DE F R OS T WH3-10 CARRY OUT 4R CHECKS. SW2 [15] O: RELAY TEST CARRY OUT 3D CHECKS. Remove the outer case and check voltage between Pin Nos.
R-890SLM CHAPTER 9. CONTROL PANEL ASSEMBLY [1] OUTLINE OF CONTROL PANEL 4) Reset Circuit The control section consists of the following units as shown in the control panel circuit. A circuit to generate a signal which resets the LSI to the initial state when power is supplied. (1) Jog Switch Unit 5) Buzzer Circuit (2) Control Unit The buzzer is responsive to signals from the LSI to emit audible sounds (tact switch touch sound and completion sound).
R-890SLM [2] SERVICING FOR CONTROL PANEL 1. Precautions for Handling Electronic Components b) On some models, the power supply cord between the control panel and the oven is long enough that they may be separated from each other.
R-890SLM CHAPTER 10. PRECAUTIONS FOR USING LEAD-FREE SOLDER 1. Employing lead-free solder The “Main PWB” of this model employs lead-free solder. This is indicated by the “LF” symbol printed on the PWB and in the service manual. The suffix letter indicates the alloy type of the solder. Example: Indicates lead-free solder of tin, silver and copper 2. Using lead-free wire solder When repairing a PWB with the “LF” symbol, only lead-free solder should be used.
R-890SLM CHAPTER 11. COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE [1] BEFORE OPERATING WARNING AGAINST HIGH VOLTAGE: Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result in severe, possibly fatal, electric shock. (Example) High Voltage Capacitor, High Voltage Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc.. WARNING: Avoid possible exposure to microwave energy.
R-890SLM [3] HIGH VOLTAGE COMPONENTS REMOVAL (HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY) To remove the components, proceed as follows. 1. CARRY OUT 3D CHECKS. 2. Disconnect the filament lead of the high voltage transformer and the high voltage wire A from the high voltage capacitor. 3. Remove one (1) screw holding earth side terminal of the high voltage rectifier assembly. 4. Remove one (1) screw holding fan duct to the oven cavity rear plate. 5.
R-890SLM CAUTION: • Do not hit the fan blade when installing because the bracket may be deformed. • Make sure that the fan blade rotates smoothly after installation. • Make sure that the axis of the shaft is not slanted. 3. Insert the tabs of the capacitor holder to the fan duct. 4. Install the fan duct to the oven cavity back plate with the one (1) screw. 6. Reinstall the chassis support to the oven cavity with the one (1) screw. 7. Refit the one(1) screw to secure the chassis support to the magnetron. 8.
R-890SLM [9] POSITIVE LOCK CONNECTOR REMOVAL Terminal 1. CARRY OUT 3D CHECKS. Positive lock¨ connector 2. Push the lever of positive lock® connector. 1 3. Pull down on the positive lock® connector. Push ® Figure C-2. Positive lock connector ® CAUTION: WHEN CONNECTING THE POSITIVE LOCK CONNECTORS TO THE TERMINALS, CONNECT THE POSITIVE LOCK ® SO THAT THE LEVER FACES YOU. Lever 2 Pull down Figure C-2. Positive lock, connector Oven lamp [10] OVEN LAMP REMOVAL 1. CARRY OUT 3D CHECKS. 2.
R-890SLM [13] BOTTOM HEATING ELEMENTS REMOVAL 1. CARRY OUT 3D CHECKS. 2. Remove the turntable motor cover from the base plate, referring to “TURNTABLE MOTOR REPLACEMENT”. 3. Disconnect the wire leads from the bottom heating element. 4. Remove the two (2) nuts holding the heater cover and heater packing to the bottom heater. 5. Remove the heater cover and the heater packing from the bottom heating element. 6. Remove the two(2) nuts holding the bottom heating element to the oven cavity. 7.
R-890SLM 2. The contacts (COM-NO) of the stop switch and the monitored latch switch open within 1.8mm gap between right side of cavity face plate and door when door is opened. 4. When the door is closed the contacts (COM-NC) of the monitor switch and monitored latch switch open. And the contacts (COM-NO) of their switches close. 3. When the door is closed, the contacts (COM-NO) of the stop switch close. 5.
R-890SLM CHAPTER 12. MICROWAVE MEASUREMENT After any repair, the microwave oven must be checked for microwave leakage to ensure continued safe operation. BS EN 60335-2-25 specifies that the maximum permitted leakage with a load of 275 ml is 50 W/m2 (equivalent to 5 mW/cm2) at a distance of 5 cm from the oven. PREPARATION The following items are required to carry out this test: 1.
R-890SLM CHAPTER 13. CIRCUIT DIAGRAMS [1] Oven Schematic SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. PLUGGED IN OVEN. 3. NOTHING APPEARS ON DISPLAY. Figure O-1(a) Oven Schematic-OFF Condition right after the oven is plugged in. SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR OPENED. 2. “ENERGY SAVED MODE TO CANCEL ENERGY SAVED MODE SET THE CLOCK” APPEARS ON DISPLAY. Figure O-1(b) Oven Schematic-OFF Condition when the oven door is opened. 13 - 1 Service_R-890SLM.
R-890SLM SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. “O” APPEARS ON DISPLAY. Figure O-1(c) Oven Schematic-OFF Condition after the oven door is closed. SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. MICROWAVE MODE SET. 3. COOKING TIME SET. 4. START BUTTON PRESSED. Figure O-2 Oven Schematic-Microwave cooking Condition SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. TOP GRILL MODE SET. 3. COOKING TIME SET. 4. START BUTTON PRESSED.
R-890SLM SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. BOTTOM GRILL MODE SET. 3. COOKING TIME SET. 4. START BUTTON PRESSED. Figure O-3(b) Oven Schematic-Grill-2 cooking Condition (BOTTOM GRILL mode) SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. TOP & BOTTOM GRILL MODE SET. 3. COOKING TIME SET. 4. START BUTTON PRESSED. Figure O-3(c) Oven Schematic-Grill-3 cooking Condition (TOP AND BOTTOM GRILL mode) 13 - 3 Service_R-890SLM.
R-890SLM SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. CONVECTION MODE SET. 3. COOKING TIME SET. 4. CONVECTION TEMPERATURE SELECTED. 5. START BUTTON PRESSED. NOTE: The top heating element, bottom heating element, fan motor and convection motor will be turned on and off according to the temperature. See “AUTO POWER CONTROL OPERATION”. Figure O-4 Oven Schematic-Convection Condition SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. COMBI 1 MODE SET. 3. COOKING TIME SET. 4.
R-890SLM SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. COMBI 2 MODE SET. 3. COOKING TIME SET. 4. MICROWAVE POWER LEVEL SET. 5. START BUTTON PRESSED. Figure O-5(b) Oven Schematic-COMBI-2 cooking Condition (Microwave and Top Grill mode) SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. COMBI 3 MODE SET. 3. COOKING TIME SET. 4. MICROWAVE POWER LEVEL SET. 5. START BUTTON PRESSED. Figure O-5(c) Oven Schematic-COMBI-3 cooking Condition (Microwave and Bottom Grill mode) 13 - 5 Service_R-890SLM.
WH1 9 2 CN-B CN-C 1 3 1 1 CN-E 1 2 3 4 5 6 7 CN-A BLU BRN ORG RED CN-E RY1 RY5 WH2 BOTTOM HEATING ELEMENT ORG BLK WHT OVEN LAMP RED ORG GRY GRY 1 2 3 4 5 6 7 8 9 BRN ORG GRY WHT BLU CN-A BLK R ED ORG BLU RED RED RED COM MONITORED LATCH SWITCH MONMITOR SWITCH N.C. NC GRY WHT WHT RED ORG COM WHT GR Y TURNTABLE MOTOR RED WHT WHT RED GRY L EARTH RED N LIVE TL BL U WH T BR N BR N MG.
R-890SLM [3] Control Unit Circuit Figure S-2. Control Unit Circuit 13 - 7 Service_R-890SLM.
R-890SLM [4] Printed Wiring Board of Control Unit 13 - 8 Service_R-890SLM.
R-890SLM [5] Printed Wiring Board of Power Unit 13 - 9 Service_R-890SLM.
R-890SLM [6] Printed Wiring Board of Switch Unit Figure S-3. Printed Wiring Board of Switch Unit 13 - 10 Service_R-890SLM.
R-890SLM 13 - 9 Service_R-890SLM.
R-890SLM PARTS LIST MICROWAVE OVEN WITH GRILL AND CONVECTION HOW TO ORDER REPLACEMENT PARTS To have your order filled promptly and correctly, please furnish the following information. 1. MODEL NUMBER 2. REF. NO. 3. PART NO. 4. DESCRIPTION MODELS R-890SLM Parts marked “*” may cause undue microwave exposure. Parts marked “S” are used in voltage more than 250V.
R-890SLM [1] OVEN PARTS 7-18 2-3 7-6 2-2 2-1 7-18 7-18 4-21 4-24 7-18 7-4 4-28 4-34 4-30 7-18 7-15 4-33 7-11 7-3 1-12 7-15 1-11 4-14 4-19 7-7 1-1 1-3 4-27 1-3 7-6 4-1 4-32 4-3 7-6 7-7 7-21 x2 7-8 7-7 x7 1-18 7-18 4-6 4-36 7-18 x2 7-9 4-4 4-37 4-5 4-32 7-12 7-13 4-18 7-17 4-25 7-16 7-4 7-3 4-26 1-8 7-6 6-3 1-3 7-18 7-17 7-18 1-10 7-1 7-6 4-16 1-7 1-13 4-35 7-10 4-8 4-23 6-4 7-5 4-10 1-5 1-20 7-20 4-11 7-14 4-7 7-2 1-15 4-17 1-17 1-16 4-
R-890SLM PARTS LIST NO.
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R-890SLM [2] DOOR AND CONTROL PANEL PARTS 5 5-4 x6 5-3 5-5 5-1 5-2 5-8 5-2-1 5-9 5-7 5-2-8 5-2-6 5-2-4 5-2-5 5-2-3 5-6 3-11 3-5 3-7 3-1 3-11 3-8 3-12 3-3 3-11 x10 3-2 3-10 3-4 3-9 3-6 5 Service_R-890SLM.
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