S/M No. : R1B4H0A002 Service Manual Microwave Oven Model: KOR-1B4H0A KOR-1B4H9A04 MCD1311ST EW13F1ST DAEWOO ELECTRONICS CO., LTD. http : //svc.dwe.co.kr Mar.
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.
SAFETY AND PRECAUTIONS CAUTION : This Device is to be Serviced Only by Properly Qualified Service Personnel. Consult the Service Manual for Proper Service Procedures to Assure Continued Safety Operation and for Precautions to be Taken to Avoid Possible Exposure to Excessive Microwave Energy. 1. FOR SAFE OPERATION Damage that allows the microwave energy (that cooks or heats the food) to escape will result in poor cooking and may cause serious bodily injury to the operator.
SPECIFICATIONS MODEL KOR-1B4H0A POWER SUPPLY 120V~60HZ, SINGLE PHASE WITH EARTHING 1500 W 1400 W MICROWAVE ENERGY OUTPUT 1100 W 1000W MICROWAVE FREQUENCY 2450MHz OUTSIDE DIMENSIONS (W X H X D) 560X344X471mm (22.0X13.5X18.5 in.) CAVITY DIMENSIONS (W X H X D) 369X246X394mm (14.5X9.7X15.5 in.) NET WEIGHT APPROX. 16.7kg TIMER 99min. 99sec. FUNCTION SELECTIONS MICROWAVE POWER SELECTIONS 10 LEVELS CAVITY VOLUME 1.3 Cu.
EXTERNAL VIEW 1.
2. FEATURE DIAGRAM 2 1 4 6 7 3 9 5 8 0 1. DOOR SEAL Door seal maintains the microwave within the oven cavity and prevents microwave leakage. 2. DOOR HOOK When door is closed, it will automatically lock shut. If door is opened while oven is operating, magnetron tube will immediately stop operating. 3. DOOR SCREEN Allows viewing of food. Microwave cannot pass through perforations in screen. 4. SPATTER SHIELD Protects the microwave outlet from splashes of cooking foods. 5.
3. CONTROL PANEL 2 M/W DEF TIMER LOCK lb 3 POPCORN 4 MORE BEVERAGE 6 7 9 q FROZEN PIZZA MEAT DINNER PLATE LESS 5 FRESH FROZEN VEGETABLE VEGETABLE POULTRY POWER FISH DEFROST 1 2 3 4 5 6 7 8 9 KITCHEN TIMER 0 CLOCK START/ SPEEDY COOK STOP/CLEAR 8 1 0 w 1. Time set pad - Used to set the cooking time and the present time. 2. Display - Cooking time, power level, indicators and present time are displayed. 3. One touch - Used to cook or reheat specific quantities of food. 4.
INSTALLATION 1. Steady, flat location. This microwave oven should be set on a steady, flat surface. 2. Leave space behind and side. All air vents should be kept a clearance. If all vents are covered during operation, the oven may be overheated and, eventually, cause oven failure. 3. Away from radio, and TV sets Poor television reception and radio interference may result if the oven is located close to a TV, radio, antenna, or feeder and so on. Position the oven as far from them as possible. 4.
OPERATIONS AND FUNCTIONS 1. Connect the main lead to an electrical outlet. 2. After placing the food in a suitable container, open the oven door and put it on the glass tray. The glass tray must always be in place during cooking. 3. Close the door securely. 4. The oven door can be opened at any time during operation by touching the door release button on the control panel. The oven will automatically shut off. To restart the oven, close the door and then touch START. 5.
DISASSEMBLY AND ASSEMBLY - Cautions to be observed when trouble shooting. Unlike many other appliances, the microwave oven is high-voltage, high-current equipment. It is completely safe during normal operation. However, carelessness in servicing the oven can result in an electric shock or possible danger from a short circuit. You are asked to observe the following precautions carefully. 1. Always remove the power plug from the outlet before servicing. 2.
1. To remove cabinet 1) Remove three screws on cabinet back. 2) Push the cabinet backward. 2. To remove door assembly 1) Remove two screws which secure the stopper hinge top. 2) Remove the door assembly from top plate of cavity. 3) Reverse the above for reassembly. NOTE : After replacing the door assembly, perform a check of correct alignment with the hinge and cavity front plate.
3. To remove door parts. A10 A11 A09 A14 A07 A05 A12 A04 A13 A08 A03 A06 A01 A02 REF NO.
4. Method to reduce the gap between the door seal and the oven front surface. (1) To reduce gap located on part ‘A’. A • Loosen two screws on stopper hinge top, and then push the door to contact the door seal to oven front surface. • Tighten two screws. M/W DEF TIMER LOCK FROZEN PIZZA POPCORN MORE (2) To reduce gap located on part ‘B’. FRESH BEVERAGE VEGETABLE MEAT POULTRY • Tighten two screws. B NOTE : A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm2.
5. To remove control panel parts. B05 B03 B04 B02 B01 REF NO. PART CODE B01 3518523400 SWITCH MEMBRANE PART NAME KOR-1B4H0A DESCRIPTION Q’TY 1 B02 3511607600 DECORATOR C-PANEL STS430 HL T0.5 1 B03 3516727000 CONTROL PANEL ABS AF-348, VT-0826 1 B04 3514326500 PCB AS KOR-1B4H0A 1 B05 7122401211 SCREW TAPPING T2S TRS 4X12 MFZN 4 REMARK (1) Remove the screw which secure the control panel, push up two snap fits and draw forward the control panel assembly.
6. To remove high voltage capacitor. 1) Remove a screw which secure the grounding ring terminal of the H.V. diode and the capacitor holder. 2) Remove the H.V. diode from the capacitor holder. 3) Reverse the above steps for reassembly. ◆ High voltage circuit wiring 7. To remove magnetron. 1) Remove a screw which secure the magnetron. 2) Remove the magnetron. 3) Reverse the above steps for reassembly.
8. To remove wind guide assembly. 1) Remove a screw which secure the wind guide assembly. 2) Draw forward the wind guide assembly. 3) Pull the fan from the motor shaft. 4) Remove two screws which secure the motor shaded pole. 5) Remove the motor shaded pole. 6) Reverse the above steps for reasembly. 9. To remove H.V.transformer. 1) Remove four screws holding the H.V.transformer. 2) Remove the H.V.transformer. 3) Reverse the above steps for reassembly.
INTERLOCK MECHANISM AND ADJUSTMENT The door lock mechanism is a device which has been specially designed to completely eliminate microwave radiation when the door is opened during operation, and thus to perfectly prevent the danger resulting from the leakage of microwave. (1) Primary interlock switch When the door is closed, the hook locks the oven door. If the door is not closed properly, the oven will not operate. When the door is closed, the hook pushes the button of the microswitch.
TROUBLE SHOOTING GUIDE Following the procedure below to check if the oven is defective or not. 1) Check grounding before trouble checking. 2) Be careful of the high voltage circuit. 3) Discharge the high voltage capacitor. 4) When checking the continuity of the switches, fuse or high voltage tranformer, disconnect one load wire from these parts and check continuity with the AC plug removed. To do otherwise may result in a false reading or damage to your meter.
CONDITION Outlet has proper voltage Fuse does not blow. CHECK RESULT CAUSE REMEDY No Continuity Defective magnetron Replace Check continuity of magnetron Check continuity of power supply cord No Continuity Open power supply cord Replace Normal Defective touch control circuit Replace Malfunction of secondary interlock switch Replace Display do not shown countdown NOTE 1 All these switches must be replaced at the same time, please refer to “Interlock Mechanism And Adjustment”.
(TROUBLE 3) No microwave oscillation even though fan motor rotates.
(TROUBLE 4) The following visual conditions inditions indicate a probable defective touch control circuit or membrane switch assembly 1. Incomplete segments, 1) Segments missing. 2) Partical segments missing. 3) Digit flickering other than normal display slight flickering. 4) " :0" does not display when power is on. 2. A distinct change in the display is not on when they should be. M/W DEF TIMER LOCK lb 3. One or more digits in the display are not on when they should be. 4.
MEASUREMENT AND TEST 1. MEASUREMENT OF THE MICROWAVE POWER OUTPUT Microwave output power can be checked by indirectly mmeasuring the temperature rise of a certain amount of water exposed to the microwave as directed below. PROCEDURE 1. Microwave power output measurement is made with the microwave oven supplied at rated voltage and operated at its maximum microwave power setting with a load of 100 ± 5cc of potable water. 2.
2. MICROWAVE RADIATION TEST CAUTION 1. Make sure to check the microwave leakage before and after repair of adjustment. 2. Always start measuring of an unknown field to assure safety for operating personnel from microwave energy. 3. Do not place your hands into any suspected microwave radiation field unless the safe density level is known. 4. Care should be taken not to place the eyes in direct line with the source of microwave energy. 5.
3. COMPONENT TEST PROCEDURE • High voltage is present at the high voltage terminal of the high voltage transformer during any cooking cycle. • It is neither necessary nor advisable to attempt measurement of the high voltage. • Before touching any oven components or wiring, always unplug the oven from its power source and discharge the capacitor. 1. High voltage transformer 1) Remove connections from the transformer terminals and check continuity. 2) Normal readings should be as follows : Secondary winding .
WIRING DIAGRAM KOR-1B4H0A 25
KOR-1B4H9A04 26
PRINTED CIRCUIT BOARD 1. CIRCUIT CHECK PROCEDURE 1. Low voltage transformer check The low voltage transformer is located on the P.C.B. Measuring condition: Input voltage: 120V / Frequency: 60Hz Terminal Voltage LOAD NO LOAD 4-7 AC 12.6 V AC 14.7 V NOTE 1. Refer to Ciruit Diagram (point 4). 2. Secondary side voltage of the low voltage transformer changes in proportion to fluctuation of power source voltage. 3. The allowable tolerance of the secondary voltage is within ± 5% of nominal voltage. 2.
MP1 MP2 Mesure point 28
3. When there is no microwave oscillation 1) When touching START pad, oven lamp does not turn on. Fan motor do not rotate, but cook indicator in display comes on. ✻ Cause : RELAY 2 does not operate. → refer to Circuit Diagram (point 3) - Check method POINT A B RELAY 2 ON -5VDC GND RELAY 2 OFF GND -12VDC STATE 2) When touching START pad, oven lamp turns on. Fan motor and turntable rotate and cook indicator in display comes on. ✻ Cause : RELAY 1 does not operate.
2. P.C.B.
3. P.C.B. LOCATION NO.
EXPLODED VIEW AND PARTS LIST 1. DOOR ASSEMBLY Refer to Disassembly and assembly 2. CONTROL PANEL ASSEMBLY Refer to Disassembly and assembly 3.
REF NO PART CODE A00 3511716000 DOOR AS KOR-1B4H0A 1 B00 3516727200 CONTROL PANEL AS KOR-1B4H0A 1 F01 3510806800 CABINET STS430 T0.
REF NO PART CODE PART NAME DESCRIPTION F28 3513702100 LEVER SW MICRO POM 1 F29 4415A17352 SW MICRO VP-533A-OF SPNO #187 200G 1 F30 4415A66600 SW MICRO VP-532A-OF/SPNO #187 200G 1 F31 4415A17352 SW MICRO VP-533A-OF SPNO #187 200G 1 F32 4415A66910 SW MICRO VP-531A-OF/SZ,-V16-FA-61 1 F33 3513700800 LEVER LOCK POM 1 F34 3513816000 LOCK PP 1 F35 3513601500 LAMP BL 120V 25W T25 C5A H187 1 F36 7121400611 SCREW TAPPING T2S PAN 4X6 MFZN 1 F37 3966820200 MOTOR SYNCRO
DAEWOO ELECTRONICS CO., LTD. 686, AHYEON-DONG MAPO-GU SEOUL, KOREA C.P.O. BOX 8003 SEOUL, KOREA TELEX: DWELEC K28177-8 CABLE: “DAEWOOELEC” S/M NO.
