How to Troubleshoot an LG Refrigerator That Won't Cool

Escrito Por: Ben Schlichter
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How to Troubleshoot an LG Refrigerator That Won't Cool

Dificuldade

Moderate

Passos

19

Tempo necessário

No estimate

Introdução

Use this guide to diagnose an LG refrigerator that’s running but not cooling in the fridge section, the freezer section, or both. You’ll learn how to inspect the evaporators and fans, check for defrost problems, clean the condenser coils, use the control board test modes (including forced defrost), and identify when the issue is likely a control board problem or a sealed-system/compressor problem that needs a technician.

    • Check whether the refrigerator section isn’t cooling, the freezer section isn’t cooling, or both sections aren’t cooling.

    • Use the section that isn’t cooling to decide which evaporator, fan, and defrost parts to inspect first.

    • Remove all shelves from the refrigerator section.

    • Remove the evaporator panel screws, including any screws hidden behind small covers.

    • Pull off the evaporator panel once the screws are removed.

    • If the panel won’t come off due to ice, run forced defrost or unplug the unit and remove the ice another way.

    • Expect screw locations and counts to vary by model.

    • Inspect the evaporator fan, sensors, and wire clusters behind the evaporator panel.

    • Check for wires that are out of place, unplugged, damaged, or missing.

    • Remove any wires that physically hold the panel in place, if needed, to fully access the area.

    • Check behind any removed wire connectors for moisture damage.

    • If you had heavy ice buildup, test the defrost heater and any defrost sensors with a multimeter.

    • Compare sensor readings to the LG thermistor resistance chart for the cabinet you’re testing.

    • Look for a light, even coat of frost on the evaporator to confirm normal operation.

    • Treat no frost as a sign the section may not be cooling at all.

    • Treat heavy frost only near where the silver lines enter the evaporator as a possible low-refrigerant clue.

    • Treat heavy frost across the entire evaporator as a defrost-system problem that needs repair.

    • Assume the evaporator fan is off when the doors are open, because these refrigerators shut fans off with the doors open.

    • Trick the door reed switches by placing magnets on both door hinges to try to make the fan run.

    • Record a video with a phone placed inside the refrigerator, close the doors, and wait 30 to 45 seconds to see whether the fan starts.

    • Use control board test mode 1 to force the fans on, if your model supports it.

    • Replace the evaporator fan if it doesn’t run during these tests and its wiring is connected.

    • Use a Phillips screwdriver to remove the two screws that hold the freezer door in place.

    • Lift up on the front of the freezer door to remove it.

    • Remove the upper freezer door the same way on a four-door unit to access the rear evaporator area.

    • Inspect the rear freezer panel for tabs you must press in or screws you must remove.

    • Remove any rail glides or sliders that block the evaporator cover, if your model uses them.

    • Remove the evaporator panel and disconnect any wires that prevent the assembly from coming free.

    • Set the panel aside so the evaporator assembly is fully visible.

    • Check whether the freezer evaporator has heavy frost, light frost, no frost, or ice concentrated in only one area.

    • Test the freezer sensors and defrost heater individually with a multimeter if there’s a lot of ice buildup.

    • Use the freezer sensor resistance chart, because the freezer values differ from the fresh-food cabinet values.

    • Test the freezer fan operation after reassembly or in test mode, because air circulation is part of the diagnosis.

    • Stop if a crossbar or trim piece won’t remove easily, because a refrigerant line may be routed behind it.

    • Remove only the evaporator panel you can safely access without forcing parts.

    • Pull the refrigerator out to create working space behind it.

    • Remove the lower rear back plate screws, then lift the plate up and off.

    • Locate the compressor, the condenser coils, and the condenser fan.

    • Confirm the condenser fan runs unless the refrigerator is in defrost.

    • Clean out any obstruction, or replace the fan if it won’t run at all.

    • Clean clogged condenser coils using a condenser brush or an air compressor with a vacuum.

    • Treat dirty coils as a common cause of poor cooling in both the upper and lower cabinets.

    • Remove the control board cover above the compressor by removing its screws.

    • Use a multimeter set to resistance or continuity to test any fuse you see on the board.

    • Touch the meter leads to each side of the fuse to check for continuity through it.

    • WARNING: Avoid touching the control board with your hands while probing, because you can get shocked.

    • Treat any reading other than OL, often around 0.01 ohms, as a good fuse.

    • Replace a failed fuse if possible, but expect some fuse replacements to require soldering or a replacement control board.

    • Unplug the refrigerator for 30 seconds, plug it back in, and wait about a minute for it to boot.

    • Locate the test button on the control board.

    • Press the test button once for about half a second and confirm you hear a single beep.

    • Confirm the front display indicates test mode 1, if your model supports it.

    • Check that test mode 1 forces the fans, compressor, and condenser fan to run so you can visually confirm fan operation.

    • Touch the compressor and feel for vibration while test mode 1 is running.

    • Treat a non-vibrating compressor in test mode 1 as a sign of a failed relay or inverter on the control board for your model.

    • Look for a blinking light on the control board or on the refrigerator’s front interface while the unit runs or while in test mode.

    • Turn off room lights if needed, because the indicator light can be hard to see.

    • Count the blinks in a repeating sequence, because codes can range from one to eight blinks.

    • Treat codes 1, 4, 6, 7, and 8 as likely control board problems or loose-wire problems.

    • Treat codes 2, 3, and 5 as sealed-system or compressor problems that aren’t realistic DIY repairs.

    • Press the test button again to enter test mode 2 and listen for freezer fans while the compressor continues running.

    • Press the test button a third time to enter forced defrost, which may show 33 on the display on some models.

    • Listen for sizzling or crackling that indicates ice melting during forced defrost.

    • Let forced defrost run for about 15 minutes to clear ice, because it should revert to normal automatically.

    • Press the test button once more to exit and reset to normal operation, which may not beep on some models.

    • Use this reset as an easy attempt to restore cooling, but don’t assume it’s a permanent fix.

    • WARNING: Treat this as a dangerous live-voltage test, and wear gloves or take extra care to avoid shock.

    • Locate the CON201 wire cluster on the control board, usually on the side with the large capacitor and heat sinks.

    • Run test mode 1 and wait 15 to 30 seconds.

    • Set a multimeter to AC voltage and probe the two right-most CON201 connectors with outgoing wires.

    • Treat 160 to 185 volts AC while running as a good reading.

    • Treat readings well above or below that as a major issue, and treat readings below 120 volts AC as likely a board problem.

    • Keep the unit in test mode while checking current draw.

    • Set the meter to a 2 to 20 amp range.

    • Clamp the meter around a single wire feeding the compressor, or around one of the two wires leaving CON201.

    • WARNING: Avoid getting shocked, especially if you clamp a wire while working near the live control board.

    • If the compressor is vibrating and running, treat a meter reading of 0.5 to 0.7 as a good range per the video.

    • Treat readings outside that range as a sign the unit may be low on refrigerant or not working properly.

    • Measure the temperature of the line leaving the compressor into the condenser, the condenser coil itself, and the copper suction line returning to the compressor.

    • Expect the condenser line and coil to be warmer than ambient air around the refrigerator.

    • Expect the copper suction line to be a little colder than ambient air because it just came from the refrigerator.

    • Look for about a 20 °F difference between the condenser coil area and ambient air as an optimal target.

    • If all three locations are about the same temperature, suspect no refrigerant or a compressor that isn’t cycling refrigerant through the system.

    • Treat sealed-system and compressor problems as beyond typical DIY repair.

    • Find the model and serial label inside the refrigerator section and look for a date code, if present.

    • If there’s no date code, read the serial number where the first digit is the year and the next two digits are the month.

    • Use the example 603 as March 2016 in the serial-number format described in the video.

    • Ask a technician what parts they’ll replace, and expect a proper repair plan to include the compressor and the filter dryer.

    • Ask how they’ll address the refrigerant leak and how they plan to check for it, such as with a UV filter dryer or a pressure test.

Conclusão

If cleaning the coils, clearing ice with forced defrost, repairing wiring issues, replacing a failed fan, or fixing a fuse restores cooling, keep monitoring the frost pattern and cabinet temperatures. If test mode won’t run, voltage at CON201 is out of range, blink codes indicate a sealed-system fault, or condenser temperatures show no heat transfer, plan on a control-board replacement or a sealed-system/compressor repair by a qualified technician.

Autor(a)

Ben Schlichter

Membro desde: 21/01/25

6447 Reputação

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