LG Refrigerator LMX25984ST Repair Manual

The LG LMX25984ST is a 25.5 cubic foot French Door Refrigerator with InstaView Door-in-Door, Smart Cooling Plus technology, linear compressor, water and ice dispenser, and smart diagnosis capabilities. This manual provides essential information for troubleshooting, component identification, safety procedures, and step-by-step repair instructions for common issues. Below are key sections covering safety, diagnostics, part replacement, and maintenance.

1. Safety Information & Precautions 2. Model Specifications & Features 3. Diagnostic Procedures 4. Component Identification & Access 5. Common Troubleshooting 6. Part Removal & Replacement 7. Electrical System 8. Refrigeration System 9. Water & Ice System 10. Control Panel & Display 11. Reassembly & Testing

Safety Information & Precautions

Before attempting any repair, review all safety warnings to prevent injury or damage.

Hazard	Precaution
Electrical Shock	Unplug refrigerator from power outlet before servicing. Discharge capacitor if applicable.
Refrigerant	Only EPA-certified technicians should handle refrigerant. Avoid open flames.
Sharp Edges	Wear cut-resistant gloves when handling evaporator coils, sheet metal, or glass.
Heavy Components	Use assistance when lifting compressor, doors, or other heavy parts.
Water Leaks	Ensure water supply is shut off before working on water line or valve.

WARNING! Failure to follow safety procedures may result in serious injury or void warranty.

Model Specifications & Features

Model: LMX25984ST
Type: French Door with Bottom Freezer
Capacity: 25.5 cu. ft. (722 liters)
Dimensions (HxWxD): 69.875" x 35.75" x 34.5"
Compressor: Linear Inverter Compressor (10-year warranty)
Defrost System: Adaptive Smart Cooling Plus
Special Features: InstaView Door-in-Door, Smart Diagnosis, Craft Ice™ Maker, Water & Ice Dispenser
Electrical: 115 VAC, 60 Hz, 7.5 Amps
Refrigerant: R-600a (Isobutane)

Diagnostic Procedures

Use the built-in Smart Diagnosis feature or manual diagnostics to identify faults.

Smart Diagnosis: Press and hold "Ice Type" and "Temp Down" buttons for 3 seconds. Follow audible tones or use LG SmartThinQ app.
Error Codes: Check control panel for flashing LEDs or error displays (e.g., "FF" = communication error).
Voltage Checks: Use multimeter to test power supply, control board outputs, and sensor resistances.
Component Testing: Isolate and test fans, compressor, defrost heater, and valves for continuity.

Tip: Document error codes and symptoms before disassembly.

Component Identification & Access

Key internal components and their locations.

Component	Location	Access Method
Control Board (Main)	Top rear behind control panel	Remove top grille and panel screws
Linear Compressor	Bottom rear, lower compartment	Remove rear service panel
Evaporator Fan	Freezer section, rear wall	Remove freezer interior back panel
Condenser Fan	Bottom front behind kick plate	Remove lower front grille
Ice Maker Assembly	Upper left freezer door	Open door, remove mounting screws
Water Valve	Bottom left rear	Remove lower left rear panel
Temperature Sensors	Various locations in fridge/freezer	Follow wiring harness

Common Troubleshooting

Symptom	Possible Cause	Diagnostic Step
Refrigerator not cooling	Compressor failure, blocked vents, faulty fan	Check compressor operation, listen for fan noise, ensure vents clear
Freezer too warm	Defrost system failure, ice buildup on evaporator	Inspect evaporator for frost, test defrost heater and thermostat
Water dispenser not working	Clogged filter, faulty valve, kinked line	Check water pressure, replace filter, test valve voltage
Ice maker not producing ice	Water supply issue, faulty fill cup, motor failure	Ensure water reaches ice maker, inspect fill cup, test motor
Display panel blank/unresponsive	Power issue, control board failure, loose connection	Check outlet power, test control board input voltage, reseat connectors
Unusual noises	Fan obstruction, compressor mount loose, debris	Inspect fans, tighten compressor mounts, clear debris

Part Removal & Replacement

General steps for replacing major components. Always disconnect power first.

Control Board: Remove top grille, disconnect wires, unscrew board, replace with new.
Compressor: Recover refrigerant (licensed tech only), disconnect electrical and tubing, unbolt, install new, evacuate and recharge system.
Evaporator Fan: Remove freezer back panel, disconnect harness, remove fan shroud screws, replace fan.
Ice Maker: Empty ice bin, disconnect water line and electrical, remove mounting screws, slide out assembly.
Water Valve: Shut off water, disconnect inlet/outlet lines and wiring, remove mounting bracket, install new valve.

CAUTION! Handle refrigerant components with care. Use proper tools.

Electrical System

Wiring diagram reference and key electrical values.

Line Voltage: 115 VAC ±10%
Compressor Resistance: Check between terminals (typical: 5-20 Ω between each pair).
Defrost Heater: ~20-40 Ω resistance.
Fan Motors: ~100-500 Ω.
Temperature Sensors (Thermistors): Resistance varies with temp (e.g., 10kΩ at 77°F).

Note: Refer to specific wiring diagram (included in manual PDF) for connector pinouts and color codes.

Refrigeration System

Key components and service points.

Linear Compressor: Variable speed, oil-less design. Check for unusual vibration or noise.
Capillary Tube & Filter-Drier: Located near compressor. Replace if system contaminated.
Evaporator Coils: Behind freezer panel. Inspect for frost pattern and cleanliness.
Condenser Coils: Behind lower front grille. Clean annually with brush or vacuum.
Service Valves: High and low side access ports for gauges (if equipped).

WARNING! Only EPA-certified technicians should service sealed refrigeration system.

Water & Ice System

Diagnosis and repair of water dispenser and ice maker.

Component	Function	Test Procedure
Water Inlet Valve	Controls water flow to dispenser and ice maker	Apply 120V AC to solenoid; listen for click; check for water flow
Water Filter	Filters impurities; replace every 6 months	Check for clog; bypass filter to test pressure
Ice Maker Assembly	Makes and ejects ice cubes	Manually advance cycle; test motor and heater continuity
Water Dispenser Switch	Activates dispenser when lever pressed	Check for continuity when pressed
Water Line	¼" polyethylene tubing from valve to dispenser/ice maker	Inspect for kinks, cracks, or leaks

Control Panel & Display

Troubleshooting and replacement of user interface.

Unresponsive Buttons: Check for moisture damage, test membrane switch continuity.
Display Segments Missing: Possible loose ribbon cable or faulty display driver.
Incorrect Temperature Reading: Calibrate or replace fresh food/freezer sensors.
Panel Removal: Pry off trim carefully, disconnect ribbon cables, remove mounting screws.

Tip: Take photos during disassembly to aid reassembly.

Reassembly & Testing

Final steps after repair.

Reinstall all panels and components securely.
Reconnect all electrical connectors and water lines.
Restore power and water supply.
Run diagnostic cycle: Press and hold "Ice Type" and "Temp Freezer" for 3 seconds to enter test mode.
Verify cooling performance: Monitor temperatures over 24 hours (fridge: 37°F, freezer: 0°F).
Test all functions: Dispenser, ice maker, door alarms, and display settings.

Final Check: Ensure no water leaks, unusual noises, or error codes.

Service Support: LG Customer Service: 1-800-243-0000. Website: www.lg.com. Genuine parts: www.lgpartsonline.com.