LG Electronics MV1825SW manual

MICROWAVE OVEN SERVICE MANUAL MODEL: LMV1825SB BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. LMV1825SW LMV1825SBQ CAUTION website http://www.lgservice.com[...]

CAUTION SAFETY PRECAUTIONS PRECAUTIONS T O BE OBSER VED BEFORE AND DURING SER VICING T O A VOID POSSIBLE EXPOSURE T O EXCESSIVE MICROW A VE ENERGY a. Do not operate or allow the oven to be operated with the door open. b. Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source, and make [...]

FOREWORD Read this Manual carefully. Failure to adhere to or observe the information in this Manual may result in exposing yourself to the Microwave Energy normally contained within the oven cavity. T ABLE OF CONTENTS (Page) SAFETY PRECAUTIONS ......................................................................................................... [...]

1-1 Rated Power Consumption ..................................................1,500W maximum (Microwave oven+Cook top lamps+Ventilation fan) Microwave Output................................................................. 1000W (IEC 60705) Adjustable 100W through 1000W, 10 steps Frequency ...........................................................[...]

2-1 CAUTIONS • DO NOT operate on a 2-wire extension cord during repair and use. • NEVER TOUCH any oven components or wiring during operation. • BEFORE TOUCHING any parts of the oven, always remove the power plug from the outlet. • For about 30 seconds after the oven stops, an electric charge remains in the high voltage capacitor. When repla[...]

3-1 INST ALLA TION PRECAUTIONS ON INST ALLA TION A. Plug the power supply cord into a 120V AC, 60Hz, single-phase power source with a capacity of 15A or 20A. B. Avoid placing the unit in a location where there is direct heat or splashing water. C. Install the unit on the mounting plate firmly. D. Place the unit as far away as possible from TV, radi[...]

CONTROL P ANEL 4-1 OPERA TING INSTRUCTIONS 25 24 4 7 9 15 22 21 8 10 17 20 23 2 5 3 6 1 12 13 11 16 14 18 19[...]

CONTROL P ANEL INSTRUCTIONS 4-2 1. DISPLAY: The Display includes a clock and indicators to tell you time of day, cooking time settings and cooking functions selected. 2. MORE: Touch this pad to add ten seconds of cooking time each time you press it. 3. LESS: Touch this pad to subtract ten seconds of cooking time each time you press it. 4. AUTO DEFR[...]

5-1 SCHEMA TIC DIAGRAM OVERALL CIRCUIT DIAGRAM[...]

5-2 MA TRIX CIRCUIT FOR TOUCH KEY BOARD REHEAT N.C N.C CUSTOM POWER PIZZA CLEAR STOP TIMER MORE TURNTABLE ON/OFF COOK POPCORN POTATO VEGETABLE VEGETABLE N.C START WARM HOLD LEVEL CLOCK SET CUSTOM LIGHT HI/LO/OFF LESS LIGHT HI/LO/OFF VENT N.C Ez-On TIMER KITCHEN N.C N.C N.C N.C DEFROST AUTO TIME COOK 3 8 COOK 9 4 2 7 6 1 5 0 N.C SENSOR SENSOR SENSOR[...]

6-1 GENERAL PRECAUTIONS IN USE A. Never operate the unit when it is empty. Operating the oven with no load may shorten the life of the magnetron. Whenever cooking dry foods (dried fish, bread, etc.) or a small amount of food, be sure to put a glass of water into the cooking compartment. The glass turntable may become hot after operating, be careful[...]

PRELIMINAR Y A. SINCE NEARLY 2,100 VOLTS EXISTS IN SOME CIRCUITS OF THIS UNIT REPAIRS SHOULD BE CARRIED OUT WITH GREAT CARE. The filament leads of magnetron carry High Voltage with respect to ground. Extreme caution must be exercised. Never plug the unit into a power source to determine which component is defective in high voltage section. B. TO AV[...]

7-2 CAUTIONS • Be sure to check microwave leakage prior to servicing the oven if the oven is operative prior to servicing. • The service personnel should inform the manufacture importer, or assembler of any certified oven unit found to have a microwave emission level in excess of 5 mW/cm 2 and should repair any unit found to have excessive emis[...]

MEASUREMENT WITH THE OUTER CASE REMOVED (1) When you replace the magnetron, measure for microwave energy leakage before the outer case is installed and after all necessary components are replaced or adjusted. Special care should be taken in measuring the following parts. - Around the magnetron - The waveguide WARNING: AVOID CONTACTING ANY HIGH VOLT[...]

IMPORT ANT NOTES: UNIT MUST BE DISCONNECTED FROM ELEC- TRICAL OUTLET WHEN MAKING REPAIRS, RE- PLACEMENTS, ADJUSTMENTS AND CONTIN- UITY CHECKS. WAIT AT LEAST ONE MINUTE, UNTIL THE HIGH VOLTAGE CAPACITOR IN THE HIGH VOLTAGE POWER SUPPLY HAS FULLY DISCHARGED. THE CAPACITOR SHOULD BE DISCHARGED BY USING INSULATED WIRE - I.E. TEST PROBE CONNECTED TO 10K[...]

7-5 HOW TO REMOVE THE F .P .C. CONNECTOR Follow the steps below as illustrated in Figures 4 and 5 to remove the F.P.C. connector. (1) Hold the edges of the plastic fastener with thumb and forefinger. (Figure 4) (2) Lift up the lever of the plastic fastener from the terminal socket by lightly pressing the lever end with forefinger. (Figure 5) (3) Re[...]

B. REMOVING THE OUT CASE(Figure 8) (1) Remove the vent grille by removing two screws securing it to the out case. (2) Remove two screws securing it to the air duct. (3) Remove the mounting plate by turning the screws (1 or 2 screws) securing it to the out case. (4) Remove two screws on the left central edge and one screws on the right central edge [...]

WIRE COLOR SYMBOL COLOR WH BK BR RD BL PK GY N.P. WHITE BLACK BROWN RED BLUE PINK GREY Not Provided Latch Board Secondary Interlock Switch Interlock Monitor Switch Primary Interlock Switch Latch Board WH (from H.V .T ransformer) YL ( from Fan Motor ) WH ( from Power Cord) WH ( from cooktop lamp ) Secondary Interlock Switch Monitor Interlock Switch [...]

V ent Grille Controller (3 screws) Door Mounting Plate (1 or 2 screws) Out Case Mount,All D. REMOVING MAGNETRON (Figures 11 Through 13) (1) Remove the vent grille by loosening two screws. (Figure 11) (2) Remove the outcase. See page 7-6. (3) Remove three tap tite screws securing the magnetron to the wave guide. (4) Remove the magnetron VERY CAREFUL[...]

E. REMOVING STIRRER F AN (Figures 14 and 15) (1) Remove one rivet ASS'Y securing it to the oven upper plate by using knife blade. (2) Rotate slightly and pull out the stirrer fan cover. (3) Remove the stirrer fan. F . REMOVING DOOR (Figure 16) (1) Remove the vent grille by two screws securing it to the outcase loosening. (2) Lift up and draw t[...]

H. ASSEMBLING DOOR (1) When mounting the door assembly to the oven assembly, be sure to adjust the door assembly parallel to the chassis. Also adjust so the door has no play between the inner door surface and oven frame assembly. If the door assembly is not mounted properly, microwaves may leak from the clearance between the door and the oven. I. R[...]

K. REMOVING THE TURNT ABLE MOTOR (1) Remove the turntable. (2) Remove the turntable shaft VERY CAREFULLY with a slotted screwdriver. (Figure 20) (3) Remove the base plate by removing 7 screws securing it to the oven cavity. (Figure 21) (4) Disconnect the leadwire from the turntable motor terminals. (5) Remove the 2 screws securing the turntable mot[...]

7-12 ADJUSTMENT PROCEDURES To avoid possible exposure to microwave energy leakage, adjust the door latches and interlock switches, using the following procedure. The Interlock Monitor and Primary Interlock Switch act as the final safety switch protecting the user from microwave energy. The terminals between “COM” and “NC” of the Interlock M[...]

7-13 TEST THE LATCH AND SWITCH SEQUENCE (5) Open the oven door slowly. Watch the door latch, the Secondary Switch. Release Rod and Lever on the switches to make sure they are zero to the body of the switches in the following sequence: - Primary Interlock Switch - Secondary Interlock Switch - Interlock Monitor Switch Adjust the latch board until the[...]

7-14 A. PRIMARY INTERLOCK SWITCH TEST When the door is opened slowly, an audible click should be heard at the same time or successively at intervals and the latches should activate the switches with an audible click . If the latches do not activate the switches when the door is closed, the switches should be adjusted in accordance with the adjustme[...]

7-15 - CAUTIONS - - DISCONNECT THE POWER SUPPLY CORD FROM THE WALL OUTLET WHENEVER REMOVINGING THE CABINET FROM THE UNIT. PROCEED WITH THE TESTS ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER. (SEE FIGURE 24) - ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST B[...]

7-16 COMPONENTS TEST PROCEDURES RESULTS HIGH-VOLTAGE CAPACITOR HIGH-VOLTAGE DIODE Measure the resistance: (1) Terminal to terminal Ohm- meter Figure 25-a (2) Terminal to case Ohm- meter Figure 25-b Measure the continuity: (1) Forward Ohm- meter Figure 26-a (1) Reverse Ohm- meter Figure 26-b Normal reading: Momentarily indicates several ohms, and th[...]

REHEAT REHEAT N.C N.C N.C N.C CUSTOM CUSTOM POWER POWER PIZZA PIZZA CLEAR CLEAR STOP STOP TIMER TIMER MORE MORE TURNTABLE TURNTABLE ON/OFF ON/OFF COOK COOK POPCORN POPCORN POTATO POTATO VEGETABLE N.C N.C START START WARM WARM HOLD HOLD LEVEL LEVEL CLOCK CLOCK SET SET CUSTOM CUSTOM LIGHT LIGHT HI/LO/OFF HI/LO/OFF LESS LESS LIGHT LIGHT HI/LO/OFF HI/L[...]

7-18 COMPONENTS TEST PROCEDURES RESULTS RELAY2 Check for continuity of relay 2 with an ohm-meter. (Remove wire leads from relay 2 and operate the unit.) NOTES: • A MICROWAVE ENERGY TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON. • MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION. • WHEN REMOVING THE WIRE LEADS FROM[...]

7-19 (2) CHECKOUT PROCEDURES FOR RELAY. - PROBLEM (A) - FAN motor and oven lamp turn on without touching START key when the door is closed. Remove the mate connector of I/O CON from the circuit board. Does the unit still operate? GOOD Replace the circuit board Replace RELAY1 - PROBLEM (B) - FAN motor and oven lamp turn on When the door is closed an[...]

7-20 NOTE: A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON. (3) CHECKOUT PROCEDURES FOR CIRCUIT BOARD The following symptoms indicate a defective circuit board. 1) The start function fails to operate but the high voltage Systems, the interlock switches, the door sensing and the relay check good. 2) [...]

7-21 PROBLEM - A: PLEASE SET TIME OF DAY does not appear in display window when power supply cord is plugged into wall outlet. PROBLEM - B: Display does not show correct numbers and/or correct indications when programmed. Check: 1. POWER SUPPLY 2. FUSE (See CHECKOUT PROCEDURES FOR FUSE BLOWING: on page 7-18) 3. OVEN CAVITY THERMOSTAT 1 1 C. TROUBLE[...]

7-22 PROBLEM - C: Display does not start countdown when ST ART key is touched. PROBLEM - D: Unit operation seems to be normal but little or no heating is produced in oven load. Check: 1. TOUCH KEY BOARD (ST ART KEY FUNCTION) Check: 1. AIR VENTS 1 1 Check continuity of connector CN2 between Pin 1(PK) and pin 3(BL) when the door is closed Check opera[...]

7-23 PROBLEM - E: Unit does not heat up even if display counts down when START key is touched for HIGH POWER cooking. Check: 1. PRIMARY AND SECONDARY INTERLOCK SWITCHES 2. THERMOSTAT 1 2 Runs Contact OK Resistance incorrect Check the continuity of H.V.C. (see page 7-16) Normal H.V.T. Resistance incorrect Normal H.V.C. Abnormal Replace H.V.D. Normal[...]

7-24 PROBLEM - F: No buzzing when touching the key, between stages or at end of cooking 1 Normal circuit board Check normal operation circuit board Replace circuit board Runs[...]

7-25 PROBLEM - G: Ventilation fan does not operate when FAN HIGH/LOW key is touched. 1 Check: 1. POWER SUPPLY 2. FUSE Contact OK NO contact Replace magnetron thermal fuse and oven thermostat Poor contact Replace circuit board Normal circuit board Contact OK Normal contact Correct seating Check contact of connector S1 (see page 7-4) Replace ventilat[...]

8-1 EXPLODED VIEW DOOR 13581A 13552A WTP004 13536A 13213A 14760A 13720D 13650A WTT028 14890A 14970A 14026A[...]

8-2 CONTROL P ANEL 24781M 24810P 268711 WTP018 * 07 23506A[...]

8-3 OVEN CA VITY 33530A 34960A 33550P WTT021 WTT027 WTT029 WTT028 WTT029 WTT027 33112U WTT022 34810Q 34930R 330342 535501 35230A WTT022 63302A 56804A 368771 63303A 36912C WTT022 330341 35026G[...]

8-4 LA TCH BOARD 466001 43501A 43500A 466003 466001 44510A WSZ084[...]

8-5 INTERIOR (I) 33390G 34370T 35889A 33052A 55892A 53550F 340511 54930F WTT021 56930G WSZ002 WTP013 53300B WSZ002 WTP002 56170D WSZ002 56851D 50CZZH WTT021 54810C 55238A WSZ002 56324A 36549S 568772[...]

8-6 INTERIOR (II) WTT028 56501A 56930V 55231C *01 568771 WTT028 56549F 55262A WTT034 36549V 56912B WTP004 WSZ002 WTT029 535502 56411A 55900A 33700A 56804A 56901A *02 *04 50FZZA WTP013 56820A[...]

8-7 INST ALLA TION WSZ133 44360A WSZ098 WWZ068 WWZ068 WSZ204 56411A 65862D 63300M 63861A WSZ203 WSZ136 65862B[...]

8-14 SCHEMA TIC DIAGRAM OF P .C.B REHEAT REHEAT N.C N.C N.C N.C CUSTOM CUSTOM POWER POWER PIZZA PIZZA CLEAR CLEAR STOP STOP TIMER TIMER MORE MORE TURNTABLE TURNTABLE ON/OFF ON/OFF COOK COOK POPCORN POPCORN POTATO POTATO VEGETABLE N.C N.C START START WARM WARM HOLD HOLD LEVEL LEVEL CLOCK CLOCK SET SET CUSTOM CUSTOM LIGHT LIGHT HI/LO/OFF HI/LO/OFF LE[...]

8-15 PRINTED CIRCUIT BOARD[...]

P/NO : 3828W5S3224 May, 2003 Printed in Korea[...]