Related Manuals for LG MH-594A
Summary of Contents for LG MH-594A
- Page 1 MICROWAVE OVEN SERVICE MANUAL MODEL : MB-394A, MH-594A CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
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Page 2: Service Information
SERVICE INFORMATION TOOLS AND MEASURING INSTRUMENTS NECESSARY TOOLS NECESSARY MEASURING INSTRUMENTS Tools normally used for TV servicing are sufficient. ¥ TESTER(VOLTS-DC, AC., Ohmmeter) Standard tools are listed below. ¥ Microwave survey meter ¥ Diagonal pliers - Holaday HI-1500 ¥ Long nose pliers HI-1501 ¥... -
Page 3: Measurement With Outer Case Removed
MEASUREMENT WITH OUTER CASE NOTES WHEN MEASURING REMOVED ¥ Do not exceed meter full scale deflection. ¥ The test probe must be removed no faster than ¥ When you replace the magnetron, measure for 1 inch/sec (2.5 cm/sec) along the shaded area, microwave energy leakage before the outer case is otherwise a false reading may result. -
Page 4: Measurement Of Microwave Power Output
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 (DT) + 0.88 X (T ) X M a load of (1000±5) g of potable water. -
Page 5: Fan Motor Assembly Removal
D. DOOR GROSS ASSEMBLY REMOVAL E. HIGH VOLTAGE TRANSFORMER 1) Open the door. REMOVAL 2) Remove the choke cover cap very carefully with a 1) Discharge the high voltage capacitor. flat-blade screwdriver. 2) Disconnect the leadwire from magnetron, high voltage CAUTION : Be careful not to damage door seal plate transformer, and capacitor. -
Page 6: Magnetron Removal
H. AIR DUCT ASSEMBLY REMOVAL J. REMOVING THE TURNTABLE MOTOR 1) Disconnect the leadwire from lamp. 1) Remove the turntable. 2) Remove the Rotating Ring. 2) Remove the mounting screw to Latch Board. 3) Lay the unit down on its back. 4) Remove the turntable motor cover. -
Page 7: Pcb Assembly Removal
K. PCB ASSEMBLY REMOVAL L. INTERLOCK SYSTEM 1) Remove the control panel assembly from the 1) INTERLOCK MECHANISM cavity. (Refer to control panel assembly removal The door lock mechanism is a device which has on previous page.) been specially designed to eliminate completely 2) Remove screws which hold the PCB SUB ASSÕY to microwave activity when the door is opened during the control panel. -
Page 8: Interlock Continuity Test
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. -
Page 9: Component Test Procedure
COMPONENT TEST PROCEDURE CAUTIONS 1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE OUTER 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. -
Page 10: High Voltage Capacitor
COMPONENTS TEST PROCEDURE RESULTS Antenna Gasket Chassis Filament 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. HIGH VOLTAGE Measure the resistance. Normal: Momentarily indicates CAPACITOR (Ohm-meter scale: Rx1000) several ohms, and then... - Page 11 COMPONENTS TEST PROCEDURE RESULTS FUSE Check for continuity of the fuse with an Normal Abnormal 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.
- Page 12 COMPONENTS TEST PROCEDURE RESULTS Disconnect the 8 pin Cooking Start connector from P.C.B. (Refer to schemetic diagram on page 4-3) Cooking Start Relay 3 RELAY 2, RELAY 3 OF P.C.B. (Wire leads removed.) Note: Relay Relay 1: Fan motor Turntable motor Oven lamp Relay 2: Microwave Relay 2...
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Page 13: Troubleshooting
TROUBLE SHOOTING WHEN YOU GET A COMPLAINT FROM YOUR CUSTOMER, EVALUATE THE COMPLAINT CAREFULLY. IF THE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE MICROWAVE OVEN. THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL. CAUTIONS 1. Check grounding before checking for trouble. 2. - Page 14 (TROUBLE 1) The following visual conditions indicate a probable defective control circuit. 1. Incomplete segments. ¥ Segment missing. ¥ Partial segment missing. ¥ Digit flickering (NOTE: Slight flickering is normal.) 2. Colon does not turn on or blink. 3. A distinct change in the brightness of one or more numbers in display. 4.
- Page 15 (TROUBLE 2) Oven does not operate at all ; Display window does not display any figures and no input is accepted. CONDITION CHECK RESULT CAUSE REMEDY Replace primary Malfunction of the Check continuity 1. Fuse blows. Continuity. and monitor monitor switch. of monitor switches.
- Page 16 (TROUBLE 3) Display shows all figures set, but oven does not start cooking while desired program times are set and START pad is touched. CONDITION CHECK RESULT CAUSE REMEDY Defective Replace Check continuity 1.Setting time does No continuity. secondary switch. secondary switch.
- Page 17 (TROUBLE 5) No microwave oscillation even though oven lamp and fan motor run (Display operates properly) CONDITION CHECK RESULT CAUSE REMEDY Defective P.C.B No microwave Disconnect the Replace P.C.B No continuity. assembly oscillation. wire leads from assembly relay 2 and check continuity Continuity.
- Page 18 (TROUBLE 6) Oven does not cook properly when programmed for the set power level (Operates properly on HIGH) CONDITION CHECK RESULT CAUSE REMEDY Output is full when Defective P.C.B. Replace P.C.B. Disconnect the Abnormal. you set lower assembly. assembly. wire leads from power level.
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Page 19: Exploded View
EXPLODED VIEW INTRODUCTION OVEN CAVITY PARTS INTERIOR PARTS BASE PLATE PARTS DOOR PARTS LATCH BOARD PARTS CONTROL PANEL PARTS... -
Page 20: Door Parts
DOOR PARTS 13581A 15006A 13536A 13552A 13213A 13720D 13352A 14026A 14970A... -
Page 21: Control Panel Parts
CONTROL PANEL PARTS 24781M 268711 23572A WTP018 26638A... -
Page 22: Oven Cavity Parts
OVEN CAVITY PARTS WTT021 33112U WTT021 35264A 33550H WNZ015 33052M 340511 35026G 33390G 35300S 34960A 35889A 34036W 36549S WTP013... -
Page 23: Latch Board Parts
LATCH BOARD PARTS WSZ085 466001 43501A 43500A 466003 44510A 466002... -
Page 24: Interior Parts
INTERIOR PARTS 568771 WSZ062 56411A 56930V 56930G 50FZZA WTT028 56201A 56549F 54974S WSZ002 55900A WTT037 56851D 56912B WSZ002 50CZZH 56851C 55262A WTT028 54810C 56324A WSZ002 56201B... -
Page 25: Base Plate Parts
BASE PLATE PARTS 56170D 63302A 63303A WTT021 65006B WSZ002... -
Page 26: Schematic Diagram Of P.c.b
SCHEMATIC DIAGRAM OF P.C.B... -
Page 27: Printed Circuit Board
PRINTED CIRCUIT BOARD...