LG Fridge LMX25986ST Service Manual PDF
The LG Fridge LMX25986ST is a premium French door refrigerator with advanced cooling technology, smart features, and energy-efficient operation. This service manual provides comprehensive technical information for authorized service technicians, including disassembly instructions, troubleshooting procedures, component specifications, and repair guidelines for the 25.8 cubic foot capacity model with dual ice makers, linear compressor, and smart diagnostics.
Product Overview
The LG LMX25986ST features French door design with bottom freezer, dual evaporators, linear compressor technology, and smart cooling system with diagnostic capabilities.
| Feature | Description |
|---|
| Capacity | 25.8 cubic feet total (fresh food: 16.5 cu ft, freezer: 9.3 cu ft) |
| Compressor | Linear Compressor with 10-year warranty |
| Ice System | Dual ice makers (craft ice + cubed ice) |
| Cooling System | Multi-air flow with dual evaporators |
| Smart Features | Wi-Fi enabled, SmartThinQ compatible |
| Door Configuration | French doors (fresh food), drawer freezer |
| Finish | Stainless steel (printproof) |
| Controls | LED touch controls with diagnostic display |
| Water Filter | LT1000P filter cartridge |
| Energy Rating | ENERGY STAR certified |
Technical Specifications
- Model: LMX25986ST
- Color: Stainless Steel
- Dimensions (HxWxD): 69.875" x 35.75" x 33.625"
- Electrical Requirements: 115V, 60Hz, 7.5A
- Refrigerant: R600a (Isobutane) 2.3 oz
- Annual Energy Consumption: 685 kWh
- Water Consumption: 10.8 gallons per 100 ice cubes
- Noise Level: 39 dB
- Weight: 326 lbs
- Warranty: 1 year parts & labor, 10 years linear compressor
Component Identification
Major components include linear compressor, dual evaporators, main control board, display board, temperature sensors, ice makers, water valve, and fan motors.
- Linear Compressor Assembly: Located at rear bottom, includes compressor and overload protector
- Main Control Board: Behind rear panel in fresh food compartment
- Evaporator Fans: Fresh food and freezer compartments
- Temperature Sensors: Multiple locations including evaporator, freezer, fresh food sections
- Ice Maker Assembly: Upper left fresh food compartment (cubed ice) and freezer (craft ice)
- Water Valve: Behind kick plate at rear
- Condenser Fan: Bottom rear behind grille
WARNING! Disconnect power before accessing electrical components.
Disassembly Procedures
Step-by-step instructions for accessing and replacing major components.
- Door Removal: Remove hinge covers, disconnect wiring harnesses, lift doors off hinges
- Control Panel Access: Remove trim bezel, disconnect ribbon cables
- Evaporator Cover Removal: Remove screws, carefully detach cover without damaging sensors
- Compressor Access: Remove rear service panel, discharge refrigerant following EPA guidelines
- Ice Maker Replacement: Remove mounting screws, disconnect water line and electrical connections
- Water Filter Housing: Turn filter 90° counterclockwise, pull straight out
CAUTION! Properly recover refrigerant before opening sealed system.
Electrical System
Detailed electrical specifications and testing procedures for all major components.
| Component | Resistance | Voltage | Test Procedure |
|---|
| Compressor | 2-5 ohms | 115V AC | Check windings for continuity |
| Evaporator Fan | 150-300 ohms | 12V DC | Check for free rotation |
| Condenser Fan | 150-300 ohms | 115V AC | Verify blade clearance |
| Temperature Sensor | 10k ohms @ 77°F | 5V DC | Measure resistance at room temp |
| Water Valve | 500-1000 ohms | 24V AC | Check coil resistance |
Refrigeration System
The sealed system uses R600a refrigerant with dual evaporators and electronic expansion valves.
- Refrigerant Type: R600a (Isobutane)
- Refrigerant Charge: 2.3 ounces ± 0.1 oz
- Compressor Oil: Polyolester (POE) oil, 6.8 oz
- Evaporator Types: Fresh food: plate type, Freezer: finned tube
- Condenser: Static type with forced air fan
- Expansion Devices: Electronic expansion valves (2)
- Filter Drier: Bi-flow type, replace after system opening
WARNING! R600a is flammable - no sparks or open flames during service.
Control System
Microprocessor-based control system with multiple temperature sensors and smart diagnostics.
- Main Control Board Functions: Temperature regulation, defrost control, compressor operation, ice maker timing
- Display Board: Touch controls, temperature settings, diagnostic codes
- Sensor Locations: Fresh food evaporator, freezer evaporator, fresh food compartment, freezer compartment
- Diagnostic Mode: Press and hold "Light" and "Ice Type" for 3 seconds
- Error Codes: Displayed as alphanumeric codes on control panel
Troubleshooting Guide
| Symptom | Possible Cause | Corrective Action |
|---|
| Unit not cooling | Compressor failure, refrigerant leak, control board | Check compressor operation, test for leaks, verify control board output |
| Excessive frost | Defrost heater, defrost thermostat, door seal | Test defrost components, check door seal integrity |
| No ice production | Water valve, ice maker, water filter | Check water supply, test valve operation, replace filter |
| Error codes displayed | Sensor failure, communication error | Refer to error code chart, test sensors and wiring |
| Unusual noise | Fan obstruction, compressor mount, ice maker | Inspect fans, check compressor mounts, verify ice maker operation |
| Water leakage | Drain clog, water line, defrost system | Clear drain tube, check water connections, inspect defrost drain |
Parts List
Key replacement parts with manufacturer part numbers.
- Linear Compressor: 6738J2004A
- Main Control Board: 6871J2006F
- Display Board: 6871J2007A
- Ice Maker Assembly (Cubed): 6346J2002A
- Ice Maker Assembly (Craft): 6346J2003B
- Water Valve: 3855J2001A
- Evaporator Fan Motor: 4935J2001A
- Temperature Sensor: 6753W2001B
- Door Gasket: MCS35227702
- Water Filter: LT1000P
Wiring Diagrams
Complete electrical schematics for main power, control circuits, and component interconnections.
- Main Power Circuit: 115V AC input, fuse protection, compressor relay
- Control Circuit: 12V DC and 5V DC regulated power supplies
- Sensor Circuit: Temperature sensor network with pull-up resistors
- Display Circuit: Touch panel interface with LED indicators
- Motor Circuits: Fan motor drivers with speed control
- Ice Maker Circuit: Water valve control and ice maker motor drivers
Note: Refer to detailed wiring diagrams in appendix section.
Safety Precautions
Critical safety information for service technicians.
- Electrical Safety: Always disconnect power before servicing. Use lockout/tagout procedures.
- Refrigerant Safety: R600a is flammable. No smoking or open flames. Use approved recovery equipment.
- Personal Protection: Wear safety glasses and gloves when handling refrigerants and sharp components.
- Lifting Safety: Use proper lifting techniques. Refrigerator weighs over 300 lbs.
- Component Handling: Static-sensitive components require ESD protection.
- Documentation: Complete all service documentation and warranty paperwork.
EMERGENCY: For refrigerant leaks, ventilate area immediately and contact supervisor.
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