If your refrigerator LG suddenly stops freezing, and the compressor is either silent or makes a short click and goes silent, the problem often lies in the engine starting system. Owners of household appliances are often lost, not knowing where exactly to look for the cause of the failure. Start relay This is a small but critical detail that provides the initial impulse to start the motor.
In models LG the design may vary slightly depending on the year of manufacture and type compressor (linear or inverter). However, in classic lines, such as GA-B409 or GC-B409, the protection and starting element is located directly on the compressor housing. Important: before any manipulations with the refrigerator’s electrical system, be sure to disconnect the device from the network by unplugging the plug from the socket.
Access to this unit is usually hidden behind the rear cover at the bottom of the unit. Inexperienced craftsmen should be extremely careful, as careless handling of the wiring can lead to a short circuit. In this article, we will analyze in detail the algorithm for searching, removing and checking the functionality of this element.
Symptoms of a faulty trigger device
Before disassembling the equipment, you need to make sure that the problem is really in the trigger mechanism. Users often confuse a relay failure with a failure of the compressor or thermostat itself. If you hear the motor trying to start, but immediately stalls, this is a sure sign that starting winding does not receive the required impulse.
It is also worth paying attention to the nature of the sound. A loud metallic click repeated at regular intervals indicates that the thermal relay is opening the circuit due to an overload. In some cases, a burning or melted plastic smell may appear, which indicates overheating of the contacts inside the part body.
Visual inspection can also provide answers. If traces of soot or deformation are visible on the inside of the casing, the part requires replacement. Inverter models LG may display an error code on the display, for example Er FF or similar, which will indicate a problem in the fan or compressor circuit, but classic models are often silent.
- 🔊 The compressor hums for 1-3 seconds and suddenly stops.
- ⚡ A distinct click is heard in the back of the refrigerator.
- 🌡️ The temperature in the chambers is rising, food begins to deteriorate.
- 🔥 The smell of burnt wiring or plastic appears.
⚠️ Attention: If The compressor is hot to the touch but does not start, do not try to turn the refrigerator on again every 5 minutes. Allow the motor to cool for at least 2-3 hours, otherwise you may completely burn out the windings.
Ignoring these symptoms can lead to more expensive repairs. Replacing a burnt-out relay costs significantly less than replacing an entire compressor. Therefore, timely diagnostics helps save budget and preserve products.
The location of the relay in various LG models
The geography of search in refrigerators LG is quite predictable. In the vast majority of models, including the popular series Door-in-Door and classic two-chamber versions, the launch control unit is mounted directly on the compressor. To get to it, you will need access to the rear wall of the unit.
You need to move the refrigerator away from the wall. Be careful not to pull sharply to avoid damaging the condenser tubes, which may be pressed against the wall or floor. In some modern models with the system No Frost access may be partially blocked by a plastic casing, which is secured with latches or screws.
On the compressor itself (black barrel) in the lower part you will see protruding wires going into a plastic box. This is the node we are looking for. In linear inverter compressors LG the design may look different: there the role of the starting device is played by an electronic board integrated into the control system, and there may not be a separate mechanical relay there in the classical sense.
You can determine the type of your compressor by the sticker on the case. If it is indicated there Linear Inverter, then independent replacement of the relay is impossible, since flashing or replacement of the control board is required. In classic models, you will see markings like MA56 or QD35.
Instructions for dismantling the protective casing
The process of removing the relay does not require complex tools, but requires care. You will need a flathead screwdriver, pliers, and possibly a Phillips screwdriver to remove the compressor protective cover. First, make sure that the refrigerator is de-energized.
On the back wall of the refrigerator, at the bottom, there is a metal or plastic panel covering the compressor zone. It can be attached with self-tapping screws around the perimeter or held on with clips. Unscrew all visible screws and carefully remove the panel.
☑️ Preparation for dismantling
After removing the panel you will see the compressor, condenser (coil) and capillary tube. At the bottom of the “barrel” there is a plastic cup into which a bundle of wires fits. It is this cup that is the housing, inside of which there is a starting and thermal relay.
To remove it, you need to carefully pull it down and at the same time shake it from side to side. Do not pull too hard, as this may damage the compressor terminals. Sometimes the part sticks due to the temperature, then light turning helps.
⚠️ Attention: There may be a container inside the casing to collect condensate or oil. Hold the removed unit vertically to prevent liquid from leaking onto the floor or electronic components.
After successful removal, you will see a unit consisting of several parts. This is usually a white or black plastic case with contacts inside. At this stage, it is important to remember or photograph the order in which the wires are connected.
Diagnostics and performance testing
After removing the part, it must be inspected. Visually, there should be no cracks on the plastic, and inside there should be no traces of burning or oxidation of the contacts. If some object rattles inside (like a coin in a jar), this means that the contact group has collapsed, and the part definitely requires replacement.
For a more accurate diagnosis, you will need a multimeter. Switch the device to resistance testing mode. Check the integrity of the thermal protection: the contacts should “ring” (resistance is close to zero). If the multimeter shows one or infinity, the circuit is broken.
The starting capacitor is also checked (if it is placed separately or built into the unit). It should not have swelling. Checking for short circuits between the contacts and the housing is also required. The presence of resistance between the contacts and the metal case indicates an insulation breakdown.
Silence
| Test parameter | Normal value | Fault symptom | Action |
|---|---|---|---|
| Thermal protection resistance | 0 Ohm (closed) | ∞ (infinity) | Replacing the relay |
| Contact appearance | Clean, without carbon deposits | Black coating, melting | Cleaning or replacement |
| Coil integrity | There is resistance | Breakage circuit | Replacing the relay |
| Sound when shaking | Rumble, knocking | Destruction of the core |
If visual inspection and testing with a multimeter did not reveal obvious defects, but the refrigerator does not work, the problem may be deeper. The compressor itself may be faulty (interturn short circuit) or the control unit. In this case, you cannot do without professional service.
Is it possible to temporarily close the contacts?
Theoretically, you can start the motor by applying voltage directly to the working winding, but this is dangerous. Without a starting winding, the motor will not gain momentum and will burn out after a few seconds. Do not do this without experience!
Replacing relays and selecting analogues
If the part is faulty, it needs to be replaced. The ideal option is to find the original by the number indicated on the body of the old relay (for example, R600 or PTR117). However, originals LG may be expensive or not available for sale.
Fortunately, starting relays are often universal. The main thing is that the parameters match: compressor power (in horsepower or watts), type of refrigerant and contact location (vertical or horizontal). Chinese analogues are several times cheaper and work no worse than the originals.
When installing a new element, make sure that it fits tightly on the compressor terminals. There should be no backlash. Connect the wires in the same order in which they were disconnected. If you mix up the wires, the compressor may hum, but not start, or the machine may immediately trip.
After assembly, do not rush to close the back cover. Plug in the refrigerator and listen. The compressor should start with a characteristic hum, after 5-10 seconds the fan (if any) should turn on, and cold air will appear. If everything works, you can fix the panel.
In some cases, it may be necessary to replace not only the relay, but also the starting capacitor, which often comes in pairs. It looks like a small cylinder next to the relay. If it is swollen or leaking, change both elements at once.
Features of linear inverter compressors
Owners of modern refrigerators LG with technology Linear Inverter should know an important nuance. Such units do not have a classic starting relay with a contact group and a coil. The piston speed is started and adjusted by an electronic control unit that converts the current.
If such a refrigerator does not turn on, you should not look for a mechanical relay, but check the inverter board. It can be located either in the lower part at the back, or be integrated into the compressor itself. Diagnostics of such systems requires special knowledge and equipment.
A common mistake is trying to install a conventional relay on an inverter motor. This is technically impossible and will lead to breakdown. If you have a model with a sticker on the compressor, most likely you have an inverter system. 10 Years Warranty on the compressor, most likely you have an inverter system.
⚠️ Attention: Repairing inverter compressors often requires resoldering electronic components or replacing an expensive board. Self-repair without a diagram may be impractical. LG often requires re-soldering electronic components or replacing an expensive board. Do-it-yourself repairs without a diagram may be impractical.
However, even in inverter models, the thermal fuse or compressor fan may fail, which will cause a startup error. Check whether the fan next to the motor spins when turned on.
Frequently asked questions and answers
Is it possible to fix a burnt-out relay if you clean the contacts?
Theoretically, you can disassemble the case, clean the contacts with fine sandpaper and put it back together. However, this is a temporary measure. The plastic inside could have already melted, changing the geometry, and the spring could have lost its elasticity. Such a relay will work from several days to a month, after which it will burn out completely. It is better to replace it.
Why does a new relay burn out after a week?
If replacement does not help, then the problem is not in the relay. Most often, the compressor itself is to blame: the piston group is jammed or an interturn short circuit has occurred. The motor draws too much current, the thermal protection of the relay trips and it overheats. Compressor diagnostics are required.
Where to buy an original relay for LG?
Original spare parts can be found in specialized stores of spare parts for household appliances or at official service centers LG. They are also available on large marketplaces, but you need to carefully check the seller and the compliance of the article.
How much does it cost to replace a relay in the service?
The price consists of the cost of the part (from 500 to 2000 rubles) and the work of the technician. On average, the service costs 2500–4000 rubles, depending on the region and the complexity of access to the compressor.
Finally, finding and replacing the relay in refrigerator LG is a task feasible for a person with minimal technical skills. The main thing is to follow safety precautions and correctly determine the type of compressor. If after replacement the part fails again, do not experiment further - call a professional.