KB-6024MS KB-6024MK KB-6024MW SERVICE MANUAL S27M275KB6025 MICROWAVE DRAWER MODELS KB-6025MS/MK/MW KB-6024MS/MK/MW Melt Soften Easy Open M I C R O WAV E D R AW E R Melt Soften 1 Easy Open M I C R O WAV E D R AW E R KB-6025MS pictured KB-6024MS pictured In the interest of user-safety the unit should be restored to its original condition and only parts identical to those specified should be used.
KB-6025MS KB-6025MK KB-6025MW PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY (a) Do not operate or allow the oven to be operated with the door open.
KB-6024MS KB-6024MK KB-6024MW WARNING TO SERVICE PERSONNEL Microwave Oven units contain circuitry capable of producing very high voltage and current, contact with following parts may result in a severe, possibly fatal, electrical shock. (Example) High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness, Heating Elements, etc.. Read the Service Manual carefully and follow all instructions. Before Servicing 1.
KB-6025MS KB-6025MK KB-6025MW MICROWAVE MEASUREMENT PROCEDURE A. Requirements: 1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external surface of the oven.
KB-6024MS KB-6024MK KB-6024MW SERVICE MANUAL PRODUCT DESCRIPTION MICROWAVE DRAWERS SCHEMATICS KB-6024MS / KB-6024MK / KB-6024MW KB-6025MS / KB-6025MK / KB-6025MW FOREWORD TEST PROCEDURE This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel and Service Information for the MICROWAVE DRAWERS, KB-6024MS, KB-6024MK, KB-6024MW and KB-6025MS, KB-6025MK, KB-6025MW.
KB-6025MS KB-6025MK KB-6025MW MICROWAVE DRAWER SPECIFICATION ITEM DESCRIPTION Power Requirements 120 Volts 14.5 Amperes, 1000 watts 60 Hz Single phase, 3 wire grounded Power Output 1000 watts (IEC TEST PROCEDURE) Operating frequency of 2450MHz Cooking Cavity Dimensions KB6024 1.
GENERAL INFORMATION KB-6024MS KB-6024MK KB-6024MW GROUNDING INSTRUCTIONS This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed and grounded in accordance with the National Electrical Code 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.
KB-6025MS KB-6025MK KB-6025MW OPERATION DESCRIPTION OF OPERATING SEQUENCE The following is a description of component functions during oven operation. the secondary interlock switch and secondary interlock relay and is mechanically associated with the drawer so that it will function in the following sequence. 8. When the drawer opens from the closed position, the primary interlock relay (RY2) and secondary interlock switch open their contacts. And contacts of the relay (RY1) remains closed.
KB-6024MS KB-6024MK KB-6024MW SENSOR COOKING CONDITION 2. The coil of shut-off relay (RY-1) is energized, but the power transformer is not turned on. 3. After about 16 seconds, the cook relay (RY-2) is energized. The power transformer is turned on, microwave energy is produced and first stage is started. The 16 seconds is the cooling time required to remove any vapor from the oven cavity and sensor. Using the SENSOR function, food is cooked without figuring time, power level or quantity.
KB-6025MS KB-6025MK KB-6025MW SCHEMATIC (OFF CONDITION) T erminal that is loc ated to the right s ide on the lamp s oc k et's bac k v iew mus t be c onnec ted to neutral wire. O nly c ertain models us e the abs olute humidity s ens or P ower T rans former (F inis h L ead) terminal mus t be c onnec ted to HO T wire (R E D) 4. L FUSE 20A 1/2W NOISE SUPRESSION COIL LINE BYPASS CAPACITOR 0.
TEST PROCEDURES PROCEDURE LETTER A KB-6024MS KB-6024MK KB-6024MW COMPONENT TEST TOUCH CONTROL PANEL ASSEMBLY TEST The 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.
KB-6025MS KB-6025MK KB-6025MW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 4) 5) 6) 7) B Reconnect all leads removed from components during testing. Re-install the covers. Reconnect the power supply cord after the covers are installed. Run the oven and check all functions. KEY UNIT TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the drawer and block it open. 3. Discharge high voltage capacitor. 4.
KB-6024MS KB-6024MK KB-6024MW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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 function. D DEFROST TEST WARNING : The oven should be fully assembled before following procedure. (1) Place one cup of water in the center of the tray in the oven cavity. (2) Close the drawer, touch the Defrost pad. Then select Steaks/Chops by touching the number pad 2.
KB-6025MS KB-6025MK KB-6025MW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 11) 12) 13) 14) 15) F Discharge high voltage capacitor. Reconnect all leads removed from components during testing. Re-install the outer case (cabinet). Reconnect the power supply cord after the outer case is installed. Run the oven and check all functions. AH SENSOR TEST Checking the initial sensor cooking condition WARNING : The oven should be fully assembled before following procedure.
KB-6024MS KB-6024MK KB-6024MW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 9-2. Place the container on the center of tray in the oven cavity. 9-3. Close the drawer. 9-4. Touch the TIMER/CLOCK pad once, the POWER LEVEL pad twice and the START pad once. And touch the number pads 1 once and the number pad 4 once. 9-5. The control panel is in automatic Sensor operation. 9-6. The oven turns off automatically, and the time for detecting moisture will be displayed.
KB-6025MS KB-6025MK KB-6025MW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST Refer to the disassembly instructions found on Page 16. G MAGNETRON ASSEMBLY TEST 1. Disconnect the power supply cord. 2. Open the drawer and keep it open. 3. To discharge high voltage capacitor, wait for 60 seconds. 4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron filament leads should indicate less than 1 ohm. 5.
KB-6024MS KB-6024MK KB-6024MW TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER I SECONDARY INTERLOCK SWITCH TEST 1. 2. 3. 4. 5. 6. 7. 8. J Disconnect the power supply cord. Open the drawer and keep it open. To discharge high voltage capacitor, wait for 60 seconds. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate an open circuit with the drawer open and a closed circuit with the drawer closed.
KB-6025MS KB-6025MK KB-6025MW TEST PROCEDURES PROCEDURE LETTER L BLOWN MONITOR FUSE TEST 1. 2. 3. 4. COMPONENT TEST Disconnect the power supply cord. Open the drawer and block it open. To discharge high voltage capacitor, wait for 60 seconds. If the monitor fuse is blown when the drawer is opened, check the primary interlock switch, secondary interlock switch and monitor switch according to the "TEST PROCEDURE" for those switches before replacing the blown monitor fuse.
KB-6024MS KB-6024MK KB-6024MW TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL The touch control section consists of the following units. 6) Power Source Circuit This circuit generates voltages necessary in the control unit from the AC line voltage. In addition, the synchronizing signal is available in order to compose a basic standard time in the clock circuit.
KB-6025MS KB-6025MK KB-6025MW DESCRIPTION OF LSI (IC-1) The I/O signal of the LSIis detailed in the following table. Pin No. Signal I/O Description Terminal to change cooking input according to the Model. By using A/D converter contained in the LSI, DC voltage in accordance with the Model in operation is applied to set up its cooking constant.
KB-6024MS KB-6024MK KB-6024MW Pin No. Signal I/O Description 45 P07 OUT Common data signal. Connected to LCD signal C4. Connected VC (+5V). Terminal not used. Segment data signal. Connected to LCD segment S24. Signal coming from touch key. When any one of J-4 line keys on key matrix is touched, a corresponding signal from P10P17 will be input into P23. When no key is touched, the signal is held at "L" level. Signal similar to P23.
KB-6025MS KB-6025MK KB-6025MW Pin No. Signal I/O 47 P05 OUT 48-52 P04-P00 OUT 53 P57 OUT Description Magnetron high-voltage circuit driving signal. To turn on and off the cook relay(RY2). In 100% power operation, the signals holds “H” level during microwave cooking and “L” level while not cooking. In other cooking modes (90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 0%) the signal turns to “H” level and “L” level in repetition according to the power level.
KB-6024MS KB-6024MK KB-6024MW HUMIDITY SENSOR CIRCUIT (1) Structure of Humidity Sensor The humidity sensor includes two thermistors as shown in the illustration. One thermistor is housed in the closed vessel filled with dry air while another in the open vessel. Each sensor is provided with the protective cover made of metal mesh to be protected from the external airflow.
KB-6025MS KB-6025MK KB-6025MW TOUCH CONTROL PANEL SERVICING A. On some models, the power supply cord between the touch control panel and the oven itself is so short that the two can’t be separated. For those models, check and repair all the controls (sensor-related ones included) of the touch control panel while keeping it connected to the oven. B. On some models, the power supply cord between the touch control panel and the oven proper is long enough that they may be separated from each other.
KB-6024MS KB-6024MK KB-6024MW 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.
KB-6025MS KB-6025MK KB-6025MW COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE WARNING AGAINST HIGH VOLTAGE: Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with the following parts may result in severe, possibly fatal, electric shock. (Example) High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
KB-6024MS KB-6024MK KB-6024MW MICROWAVE DRAWER DISASSEMBLY WARNING: Follow all safety precautions as stated at the beginning of this Service Manual before proceeding! 1. Before removing Microwave Drawer, take measures to protect the Drawer louver by either removing the louver or by letting the louver over hang off flat protected surface (Fig 1). x2 Fig. 1 2. Open the Drawer to access the 4 mounting screws holding the unit on to the wall or cabinet opening. (Fig 1). Louver 3.
KB-6025MS KB-6025MK KB-6025MW 7. To remove the Control Panel Frame Assembly, remove the (5) screws holding the CP frame to the C/P angle in the back (Fig 3). Fig. 3 8. Unsnap the top C/P frame assembly away from the C/P frame and unplug all wires. The C/P frame assembly is now free. At this point, you will have access to all parts of the Microwave Drawer. POWER CORD REPLACEMENT 1. Un-hook the black and white AC terminals from the Noise Filter PWB and green ground wire from the back plate. (Fig 4).
KB-6024MS KB-6024MK KB-6024MW STOP SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL 1. Follow the Microwave Drawer disassembly as previously stated 2. Open the drawer and keep it open. in the top position, located on the left side of the unit. 3. To discharge the high voltage capacitor, wait for 60 The door sensing switch by itself on the right side of the seconds. unit. 4. Remove the screw holding the latch hook to the oven 2. Re-connect wire leads to each switch. Refer to pictorial flange.
KB-6025MS KB-6025MK KB-6025MW DRAWER/SLIDE RAIL REMOVAL DRAWER ASSEMBLY AND CHOKE REMOVAL 1. Follow the Microwave Drawer disassembly as previously stated 2. Open the drawer and keep it open. 3. To discharge the high voltage capacitor, wait for 60 seconds. 4. Remove the both right and left side panels. 5. Remove (2) Drawer Support Covers from Choke Cover as shown in (Fig. D-1). 6. Insert a putty knife (thickness of about 0.5mm) into the gap between the choke cover and the door frame. 7.
KB-6024MS KB-6024MK KB-6024MW SWITCH ANGLE REMOVAL/ADJUSTMENT SWITCH ANGLE REMOVAL Fig. S-1 (Locate either the right or left switch angle) 1. 2. 3. 4. Follow the Microwave Drawer disassembly as previously stated Open the drawer and keep it open. To discharge the high voltage capacitor, wait for 60 seconds. To remove switch, remove screw (1) holding switch to switch angle (Fig. S-1). 5. To replace switch angle, remove bottom cover and remove the 2 screws holding the switch lever (Fig. S-2). 6.
KB-6025MS KB-6025MK KB-6025MW AUTO DRAWER GEAR REMOVAL/INSTALLATION (This procedure requires a 14" or greater phillips head screwdriver) 1. Disengage the power supply to the unit. 2. Open the drawer and keep it open. 3. Remove the top cover and right side cabinet. 4. Unhook wiring connector to Auto Drawer Gear motor. 5. Remove the (3) screws holding the auto drawer gear to the bottom cavity angle (Fig. G-1). 6. Disengage (pull) Auto Drawer Gear motor from rack gear (careful not to touch PWB). 7.
KB-6024MS KB-6024MK KB-6024MW 2 1 4 3 6 5 A A RED H 3 BLK BLK 2 WHT 1 GRN WHT N WHT NOISE FILTER BOARD Power Supply cord 120V 60Hz to Back Plate WHT 4 3 RED CN502 2 GRN B 1 BLK ORG 3 BLK CN501 2 1 GRY CN502 B ORG ORG (SWITCHING POWER SUPPLY) BLK RED GRN MAGNETRON THERMAL CUT-OUT OVEN THERMAL CUT-OUT 7 ORG 6 CNA C WHT 5 4 3 RED RED BLK 2 N.C. 1 BRN GRY MONITOR SWITCH 3 CNB 2 1 GRY C WHT COOLING FAN MOTOR COM. BLK T1 ORG RY1 N.O.
KB-6025MS KB-6025MK KB-6025MW 2 1 CN-A A-7 3 T1 PA154DR FUSE AC 120V 60Hz D1 -- D4 1N4002L x4 5 5 CN-H D4 D1 D3 8 D2 + C1 1 1000uF/50V A-5 6 VR H-1 VRS1 10G471K 0.1uF/50V C2 A 2.5A 4 3 A K-1 GND H-3 K-3 INT B H-2 B K-2 RY5 D12 SW Reg. PWR H-8 C H- 9 C 502-3 SW Reg. OUT +24V E-3 J10 H-11 K-8 RY2 MICRO D N.O. D5 D H-4 K-4 H-6 K-6 COM E RY1 N.O. COM J11 0.1u 250V (C11) COM (O.
FM (RY4) SM (RY3) +24V +24V 502-1 SLIDE M 6 E-1 N-5 N-4 N-3 N-2 N-1 E-3 K-8 K-7 K-5 M-5 K-6 M-3 M-2 M-1 K-4 M-6 M-7 M-4 F-1 F-2 F-3 K-2 K-3 CN-F + CN-N CN-M CN-E 2K + - + D20 7 100 - Q26 Q25 Q95 Q22 1 C20 1.5K R69 KRC101S KRC101S KRC101S R24 10K Q23 4 8 KRC101S 10K R56 10K R58 KIA358 + 3 IC-5 2 KRC101S KRA102S Q97 R95 100 R96 R22 270 C21 10uF/35V KRC101S Q20 KRA224S Q21 10K R21 6 5 3.32KD R41 1.
KB-6025MS KB-6025MK KB-6025MW 1 2 4 3 5 6 A A B B 11 D5 2 RY2 DIP D12 D7 R3 1 J11 C10 J10 N.O. COM. RY3 D CNB D10 D3 D2 D1 C1 1 Q1 D N.O. COM. R10 R1 ZD1 C2 D4 C RY1 CNH C RY5 1 8 1 D11 1 3 RY4 E R11 E T1 F VRS1 4 3 P 7 CNA C11 FUSE F 2.5A 3 G G H H Figure S-4.
3 4 R6 K 2 1 ZD2 1 Q2 B C E R7 WHA CNK 6 C3 + 8 Q3 I C O G C3 R22 C20 9 8 1 CNM 5 Q4 I C O R8 CNX 1 2 ZD4 C5 C6 R11 C10 C8 + C21 + C8 R46 R21 R106 R105 R104 CNJ CF1 CF1 16 C13 J2 2 1 3 J1 J3 J4 J6 K R40 1 R36 R38 R37 R35 IC6 5 4 CNF 3 3 C90 1 S0 C3 S0 C0 C0 R68 R107 R103 R102 R101 R100 C44 D41 C54 D40 R42 R115 C103 R114 C102 R112 C100 C41 C30 C43 R44 Q24 R113 C101 R41 Q95 + C90 C90 R98 R96 R99 R95 1 SP R69 CNN CNN SP S0 5 1 D96 K
KB-6025MS KB-6025MK KB-6025MW CONTROL PANEL PARTS LIST Note: The parts marked “∆” may cause undue microwave exposure. The parts marked “*” are used in voltage more than 250V. REF. NO. 1-1 1-2 1-2 1-2 1-2 1-3 1-3 1-3 1-3 1-3 1-3 1-4 1-5 1-6 1-6 1-7 1-8 PART NO.
KB-6024MS KB-6024MK KB-6024MW BOTTOM COVER PARTS LIST Note: The parts marked “∆” may cause undue microwave exposure. The parts marked “*” are used in voltage more than 250V. REF. NO. 2-1 2-1 2-2 2-2 2-3 2-4 2-4 2-5 2-5 2-6 2-7 2-8 PART NO.
KB-6025MS KB-6025MK KB-6025MW MICROWAVE DRAWER PARTS LIST Note: The parts marked “∆” may cause undue microwave exposure. The parts marked “*” are used in voltage more than 250V. REF. NO.
KB-6024MS KB-6024MK KB-6024MW REF. NO. 3-48 3-49 3-50 3-51 3-52 3-53 3-54 3-55 3-56 3-57 3-58 3-58 3-58 3-58 3-58 3-58 3-59 3-60 3-61 3-61 3-61 3-61 3-61 3-61 3-62 3-63 3-64 3-65 3-66 3-67 3-68 3-69 3-70 3-71 3-71 3-72 3-72 3-73 3-74 3-75 3-75 3-76 3-77 3-78 3-79 PART NO.
KB-6025MS KB-6025MK KB-6025MW 2 1 4 3 6 5 MICROWAVE DRAWER 3-28 3-14 3-28 A 3-28 A 3-28 3-40 3-55 3-73 3-49 3-5 3-29 3-11 3-28 3-68 3-28 3-28 3-28 3-71 B 3-27 3-28 3-28 3-15 3-28 3-27 3-75 3-22 3-28 3-28 3-28 3-28 3-13 3-26 3-62 3-10 3-28 3-2 3-28 3-4 3-54 3-48 3-1 3-28 3-12 3-28 3-57 3-9 3-24 3-28 3-44 3-42 3-3 3-25 3-46 C B 3-39 3-45 3-28 3-18 3-63 3-46 3-53 C 3-6 3-36 3-56 3-28 3-10 3-32 3-8 3-52 3-7 3-51 3-28 D 3-19 3-10 3-41 3-
KB-6024MS KB-6024MK KB-6024MW PACKING PARTS LIST Note: The parts marked “∆” may cause undue microwave exposure. The parts marked “*” are used in voltage more than 250V. REF. NO. 4- 1 4- 2 4- 3 PART NO.
KB-6025MS KB-6025MK KB-6025MW COPYRIGHT © 2007 BY SHARP CORPORATION ALL RIGHTS RESERVED. No part of this publication may be reproduced, stored in retrieval systems, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher. 2007 SHARP CORP. (7R2.00E) Printed in U.S.