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Website http://biz.lgservice.com MICROWAVE OVEN SERVICE MANUAL MODEL: MC-806BLR CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. August, 2004 Printed in Korea P/NO : 3828W5S3936...
SAFETY PRECAUTIONS 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. PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY...
CAUTIONS Unlike other appliances, the microwave oven is MICROWAVE RADIATION high-voltage and high-current appliance. Personnel should not be exposed to the microwave Though it is free from danger in ordinary use, energy which may radiate from the magnetron or extreme care should be taken during repair. other microwave generating device if it is improperly used or connection.
INSTALLATIONS BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY. Installing microwave oven Earthing Instructions 1. Empty the microwave oven and clean inside it with a This microwave oven is designed to be used in a fully soft, damp cloth. Check for damage such as earthed condition.
OPERATING INSTRUCTIONS Features Control Panel 1. Grill: To select grill cooking. 2. MICRO POWER: To select micro power cooking and cooking power levels. 3. AUTO COOK: To select auto cook. 4. CLOCK: To set the time of day. 5. AUTO ROAST 6.
Operating Sequence The following is a description of component functions 6. Combination cooking during oven operation. Desired convection Combination temp(100°C~250°C) 1. Setting the clock Plug the power Grill Set the cord into an Clock correct hour electric outlet Desired Desired power level cooking Start (20%, 40% or 60%)
Circuit Description and relay 2 and/or secondary switch fail to open, the • As the door is closed, the contact of MONITOR 10A fuse opens due to the large current surge caused SWITCH opens. This switch creates the short circuit to by the monitor switch activation which in turn stops blow 10 A fuse during operation under abnormal magnetron, oscillation.
SERVICE INFORMATION Tools and Measuring Instruments NECESSARY TOOLS NECESSARY MEASURING INSTRUMENTS Tools normally used for TV servicing are sufficient. Standard tools are listed below. • TESTER (VOLTS-DC, AC, Multmeter) • Diagonal pliers • Microwave survey meter • Long nose pliers —Holaday H1-1500, Hi-1501 •...
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MEASUREMENT WITH THE OUTER NOTES WHEN MEASURING CASE REMOVED • Do not exceed meter full scale deflection. • The test probe must be removed no faster than • When you replace the magnetron, measure microwave 1 inch/sec (2.5 cm/sec) along the shaded area, energy leakage before the out case is installed and otherwise a false reading may result.
Measurement of Microwave Power Output • Microwave power output measurement is made with • The microwave power output P in watts is calculated the microwave oven supplied at its rated voltage and from the following formula : operated at its maximum microwave power setting with 4187 x (∆T) a load of (1000 ±...
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D. DOOR GROSS ASSEMBLY REMOVAL Remove door 1) Open the door. 2) Remove the choke cover cap very carefully with a flat- Door seal plate blade screwdriver. CAUTION : Be careful not to damage door seal plate with the screwdriver. 3) Lift up and push the door.
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E. MAGNETRON REMOVAL 2. When replacing the magnetron, be sure to install the 1) Disconnect the leadwire from high voltage magnetron gasket in the correct position and be sure transformer and high voltage capacitor. that the gasket is in good condition. 2) Carefully remove the mounting screws holding the 3.
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F. NOISE FILTER ASS'Y HIGH VOLTAGE H.V. Transformer DIODE, HIGH VOLTAGE CAPACITOR, AND COOLING FAN MOTOR REMOVAL 1) Disconnect lead wires from the noise filter ass'y and remove screw securing the noise filter earth wire to the back plate. 2) Push two hook of the guide suction and lift up the rear of noise filter ass'y.
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J. TURNTABLE MOTOR REMOVAL K. INTERLOCK SYSTEM 1) Remove the turntable. 1) INTERLOCK MECHANISM The door lock mechanism is a device which has been 2) Remove the turntable shaft VERY CAREFULLY with specially designed to completely eliminate microwave a slotted screw driver. activity when the door is opened during cooking and 3) Lay the set down on its back.
Interlock continuity Test WARNING : FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION EMISSION, REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS. TYPE NO.SZM-V 16-FA-63 OR VP-533A-OF FOR PRIMARY SWITCH TYPE NO.SZM-V 16-FA-62 OR VP-532A-OF FOR MONITOR SWITCH TYPE NO.SZM-V 16-FA-63 OR VP-533A-OF FOR SECONDARY SWITCH B.
Component Test Procedure CAUTIONS 1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE OUT CASE FROM THE UNIT. PROCEED WITH THE TEST ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER.
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COMPONENTS TEST PROCEDURE RESULTS Antenna Gasket Chassis Filament Terminals NOTE: When testing the magnetron, be sure to install the magnetron gasket in the correct position and be sure that the gasket is in good condition. Measure the resistance. HIGH VOLTAGE Normal: Momentarily indicates (Multi-meter scale : R x 1000) CAPACITOR...
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COMPONENTS TEST PROCEDURE RESULTS FUSE Check for continuity of the switch with a Normal Abnormal (Wire leads removed.) Multi-meter. NOTE : If the fuse is blown, check the primary, the secondary, and the monitor switches, H.V.D. and H.V.C. before replacing the fuse. If the fuse is blown by improper switch operation replace the defective switch and the fuse at the same time.
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COMPONENTS TEST PROCEDURE RESULTS Measure the resistance. Normal : COM-230V : Approx. 150 Ω CIRCULATION MOTOR (Multi-meter scale : R x 1) COM-24V : Approx. 20 Ω (Wire leads removed) Abnormal : Infinite or several ohm. (BN) 230V(BL) (YL) NOTE: ) = WIRE COLOR Normal : Approx.
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COMPONENTS TEST PROCEDURE RESULTS Cooking Start RELAY 3,4 OF P.C.B (Disconnect the 7 pin connector from P.C.B) See Schematic Dagram on page 9) Cooking Start RELAY 2,3,4 OF P.C.B (Wire leads removed.) RY2 : Microwave RY3 : Grill RY5 : Convection Check continuity between MEMBRANE KEY switch terminals, by pressing an...
Trouble Shooting Guide CAUTIONS 1. Check grounding before checking for other trouble. 2. Be careful of the high voltage circuit. 3. When checking the continuity of the switches or transformer, disconnect one lead wire from these parts and then check continuity without turning the power source on. 4.
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(TROUBLE 2) Oven does not at all even thought MOTOR and P.C.B program. TEST PROCEDURE OR CONDITION CAUSE CORRECTION No input can be Defective tact switch key of Test procedure tact switch programmed. P.C.B. key of P.C.B. Some inputs can not be Loose connection.
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(TROUBLE 3) Oven does not operating microwave cooking TEST PROCEDURE OR CONDITION CAUSE CORRECTION Oven does not go into a Primary and secondary Test procedure primary and cook cycle when START key interlock switches defective secondary switches. is touched. or out of adjustment. Defective flat cable of Test procedure flat cable of P.C.B.
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(TROUBLE 3) Oven does not operating microwave cooking TEST PROCEDURE OR CONDITION CAUSE CORRECTION Test procedure relay 2 of No microwave oscillation. Defective relay 2 of P.C.B. P.C.B. Defective high voltage Test procedure high voltage transformer. transformer. Defective high voltage Test procedure high voltage capacitor.
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(TROUBLE 4) Oven does not operate convection cooking TEST PROCEDURE OR CONDITION CAUSE CORRECTION Defective circulation motor Check and repair C-Motor wire Convection indicator lights wire ass'y. ass'y. (COM:YL, 24V:BN, 230V:BL) but oven does not go into cook cycle when START key is touched.
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(TROUBLE 5) Oven does not operating Grill cooking TEST PROCEDURE OR CONDITION CAUSE CORRECTION Test procedure relay 3 of Grill indicator lights Defective relay 3 of P.C.B. P.C.B. but oven does not go into cook cycle when START key is touched. Open or loose wire Check and repair wiring.