The LG LMXS27626S is a 27 cubic foot French Door Refrigerator with dual ice makers, linear compressor, smart cooling technology, door-in-door design, and smart diagnostics. This service manual provides authorized technicians with essential information for installation, maintenance, troubleshooting, and repair. Below are key sections covering safety, specifications, disassembly, component testing, error codes, and wiring diagrams.
Before servicing, read all safety warnings. Disconnect power before accessing internal components.
| Hazard | Precaution |
|---|---|
| Electrical Shock | Unplug unit or disconnect circuit breaker before servicing. Verify no voltage with multimeter. |
| Refrigerant | Only EPA-certified technicians may handle refrigerant. Use proper recovery equipment. |
| Sharp Edges | Wear cut-resistant gloves when handling evaporator coils, sheet metal, or tubing. |
| Heavy Components | Use two people when lifting compressor or condenser assembly. |
| Flammable Materials | Keep away from open flames when checking for gas leaks with bubble solution. |
Proper installation ensures optimal performance and longevity.
WARNING! Improper leveling can cause door alignment issues and cooling problems.
Key serviceable components and their access points.
| Component | Location | Access Method |
|---|---|---|
| Main Control Board | Top rear, behind grill | Remove rear top grill (2 screws) |
| Linear Compressor | Bottom rear | Remove rear lower kickplate |
| Evaporator Fan Motor | Freezer section rear wall | Remove freezer interior back panel |
| Condenser Fan Motor | Bottom rear near compressor | Remove rear lower grill |
| Ice Maker Assembly | Upper left refrigerator door | Open door, remove screws on ice maker cover |
| Water Filter | Upper right refrigerator interior | Push button and turn filter counterclockwise |
| Temperature Sensors | Various locations in fridge/freezer compartments | See wiring diagram for exact positions |
Step-by-step removal of major components for replacement.
CAUTION! Label all wires and take photos during disassembly to ensure proper reassembly.
Voltage, resistance, and continuity values for key components.
| Component | Test Points | Normal Value |
|---|---|---|
| Linear Compressor | Terminals P-C, P-S | 2-10 Ω (varies with temperature) |
| Evaporator Fan Motor | Between terminals | 200-400 Ω |
| Condenser Fan Motor | Between terminals | 150-300 Ω |
| Defrost Heater | Across terminals | 20-40 Ω |
| Thermistor (Fridge) | At 77°F (25°C) | 10 kΩ ± 5% |
| Door Switch | Depressed/Released | Closed/Open circuit |
Note: All resistance measurements should be taken with component disconnected from circuit.
LED error codes displayed on control panel or through smart diagnostics.
| Code | Description | Probable Cause |
|---|---|---|
| FF / 88 | Communication Error | Main board failure, wiring harness issue |
| PF | Power Failure | Power interruption > 2 minutes (normal) |
| dH | Door Open Alert | Door ajar > 5 minutes |
| CE | Communication Error with Display | Display board or connecting cable fault |
| tS | Temperature Sensor Error | Open/short in fridge or freezer sensor |
| IE | Ice Maker Error | Ice maker motor stuck, water supply issue |
| LE | Linear Compressor Error | Compressor overload, start capacitor, board fault |
Reset: Unplug for 1 minute to clear temporary codes. Persistent codes require component testing.
Verification procedures after repair or installation.
Key replacement parts with OEM numbers.
| Part Description | Part Number | Qty |
|---|---|---|
| Main Control Board (PCB) | MCL73844503 | 1 |
| Linear Compressor Assembly | 6738B2002T | 1 |
| Evaporator Fan Motor | 5309FR2006A | 1 |
| Condenser Fan Motor | 5309FR2005B | 1 |
| Ice Maker Assembly (Complete) | 6738B2001A | 1 |
| Refrigerator Door Gasket | MAB73844502 | 1 |
| Freezer Drawer Gasket | MAB73844501 | 1 |
| Water Filter (LT1000P) | 5230JA2006A | 1 |
| Temperature Sensor (Fridge) | MCL73844504 | 1 |
| Door Switch Assembly | MCL73844505 | 2 |
Note: Refer to official LG parts catalog for the most current part numbers and availability.
Simplified connection overview for major electrical systems.
Main Power Circuit: L1 (Hot) → Main Board → Compressor Relay → Linear Compressor. Neutral tied to board ground.
Control Circuit: 5V DC from board powers display, sensors, and relay logic.
Sensor Network: All thermistors connect in parallel to main board analog inputs with 10kΩ pull-up resistors.
Ice Maker Circuit: 120V AC from board → Ice Maker Solenoid → Water Valve. Separate DC circuit controls motor and position switch.
For complete schematic: See fold-out diagram included with physical manual or download from LG service portal.
Systematic approach to common problems.
| Problem | Step 1 | Step 2 | Step 3 |
|---|---|---|---|
| Refrigerator not cooling | Check for error codes on display | Verify compressor is running (listen/feel) | Test evaporator fan operation in freezer |
| Freezer too warm, fridge cold | Check freezer evaporator for frost buildup | Test defrost heater for continuity | Verify defrost thermostat operation |
| Ice maker not producing ice | Check water supply (filter installed, valve open) | Manually activate ice maker test mode | Inspect ice maker mold thermostat and motor |
| Unusual noise (buzzing/humming) | Identify source (rear bottom = compressor/fan) | Check for loose panels or foreign objects | Verify unit is level and not touching walls |
| Display blank, unit dead | Verify power at outlet (120V) | Check main board fuse (5A on board) | Test incoming power to main board connector |
Advanced Diagnostics: Use LG Smart Diagnosis via phone app (hold Temp Down button for 3 seconds) to transmit error data to LG support.
Service Support: LG Service Network: 1-800-243-0000 or visit www.lg.com/us/support