LG Electronics MS3447GRS service manual Some inputs cannot be programmed, Continuity No continuity

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(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.One or more digits in the display are not lighting.

5.Display indicates a number different from one touched, for example, key in 5 and 3 appears in the display.

6.Specific numbers (for example 7 or 9) will not display when key pad is touched.

7.Display does not count down with time blinking or up with clock operation.

8.Display obviously jumps in time while counting down.

9.Display counts down too fast while cooking.

10.Each indicator light does not turn on after setting cooking cycle.

11.Display time of day does not reappear when cooking is finished.

CONDITION

1.No input can be programmed.

2.Some inputs cannot be programmed.

3.Display shows a number or figure different from one touched.

4.Random programming when touching other pads.

5.Display is fixed at some figure and can not accept any input.

CHECK

Check the conn- ection between membrane key assembly and PCB assembly.

Replace key membrane assembly and check operation.

RESULT

Continuity.

No continuity.

Everything works as specified.

Still have trouble.

CAUSE

Defective PCB assembly.

Loose connection.

Defective key membrane assembly.

Defective PCB assembly.

REMEDY

Replace PCB assembly.

Connect them tightly.

Replace key membrane assembly.

Replace PCB assembly.

Copyright © 2007 LG Electronics. Inc. All right reserved.

5-12

LGE Internal Use Only

Only for training and service purposes

 

 

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Contents Microwave Oven Safety Precautions Microwave RadiationContents Approx % of Full power SpecificationsFull power throughout the cooking time Approx %Microwave Radiation AntennaInstalling InstallationEarthing Instructions More Pressing More will add 10 seconds to the cooking time Features Control PanelOperating Instructions Cooking timeOperating Sequence Schematic Diagram Circuit Description Microwave Leakage Test Service InformationTools and Measuring Instruments Necessary ToolsMeasurement with a Fully Assembled Oven Measurement with Outer Case RemovedAround the magnetron Waveguide Power Supply Cord Measurement of Microwave Power OutputDisassembly and Adjustment Control Panel AssemblyPCB Assembly Removal Door Main Assembly RemovalRemoving the Turntable Motor AIR Duct Assembly RemovalMagnetron Removal Very CarefullyHigh Voltage Capacitor and Diode Removal FAN Motor Assembly RemovalHigh Voltage Transformer Removal Interlock SystemMonitor Switch Test Primary Interlock Switch TestSecondary Interlock Switch Test SwitchesFilament Winding Primary Terminal Component Test ProcedureHigh Voltage Transformer Wire leads removed MagnetronCapacitor High VoltageMeasure the resistance Normal Momentarily indicates Measure the continuity Forward Normal ContinuityLevel PowerRelay FAN MotorTrouble Shooting Condition Cause RemedySome inputs cannot be programmed Defective PCB assemblyDefective key membrane assembly Defective PCB assembly Continuity No continuityReplace power supply cord Check continuity Continuity Monitor Switch with Door closedPower supply Fuse blowsDefective PCB Replace PCB Assembly Setting time Check continuitySecondary switch Power source Rating voltage Voltage Normal DisconnectAbnormal Defective PCB assembly Defective PCB assembly Defective high voltage transformerReplace high voltage diode Replace magnetron Exploded View IntroductionDoor Parts Control Panel Parts Oven Cavity Parts Larch Board Parts Interior Parts WTT021 WTP004 56501A 54974TBase Plate Parts

MS3447GR, MS3447GRS specifications

The LG Electronics MS3447GRS and MS3447GR are innovative microwave models designed to enhance your cooking experience with a blend of advanced technology and user-friendly features. Both models are built to accommodate various culinary needs, making them ideal for any kitchen.

One standout feature of the MS3447GRS and MS3447GR is the Smart Inverter technology. This technology provides precise cooking power control, allowing users to defrost, reheat, and cook food evenly. This results in better texture and flavor retention in various dishes, surpassing traditional microwaves that may only provide two or three levels of heating.

Another significant characteristic is the EasyClean interior. This feature ensures that maintaining a clean microwave is hassle-free. The interior surface can be wiped down easily, helping to prevent the buildup of food residues and odors, which allows for a more hygienic cooking environment over time.

The LG MS3447GRS and MS3447GR also come equipped with a range of auto-cook options. These preset cooking modes simplify meal preparation, allowing users to cook a variety of dishes such as popcorn, baked potatoes, and frozen meals with just the push of a button. This is particularly beneficial for busy individuals and families looking to streamline their cooking process.

Additionally, these models boast a sleek and modern design that seamlessly integrates into any kitchen decor. The clean lines, polished finishes, and intuitive control panel make it an attractive and functional appliance. The user interface is designed for ease of use, with clear indicators and a layout that simplifies operation.

Both microwaves feature a spacious interior, which provides ample room for a variety of cookware sizes, making it easier to heat larger dishes. The turntable ensures that food is cooked evenly, while the powerful wattage guarantees efficient cooking times.

In conclusion, the LG Electronics MS3447GRS and MS3447GR microwave models are exemplary devices that combine cutting-edge technology with practical features. Their Smart Inverter, EasyClean technology, and flexible cooking options cater to the needs of modern kitchens, affirming LG's commitment to innovation and quality in kitchen appliances. Whether you're reheating leftovers or preparing a family meal, these microwaves make cooking simpler and more efficient.
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