Faced with a situation where your Samsung refrigerator suddenly stops freezing, but continues to hum or, conversely, is silent, many owners panic. However, often the cause of failure is not an expensive compressor, but a relatively cheap part - the start relay. This small device is responsible for starting the engine, and its failure is one of the most common problems in household appliances. If you hear clicks, a hum without starting, or a complete lack of response to turning on, diagnosing this particular unit will be the first step to restoring the operation of the unit.
Before starting disassembly, you need to make sure that the problem lies precisely in the electrical start circuit, and not in the lack of voltage in the socket or interrupted cord. Start relay is a compact unit that is attached directly to the compressor housing. Its main task is to briefly apply increased current to the motor winding to start it, and then turn off. If this mechanism is broken, the motor either does not start at all, or tries to do so unsuccessfully, making characteristic sounds. Understanding the principle of operation will help you quickly identify the malfunction.
In this article we will analyze in detail the algorithm of actions that will allow you to carry out diagnostics yourself. You don't need complex industrial equipment, just a basic set of tools and attentiveness. We will look at visual inspection, multimeter testing, and alternative testing methods that are available at home. Critical
⚠️ Attention: Before starting any diagnostic work, be sure to unplug the refrigerator from the outlet. The residual voltage in the capacitors can persist for several minutes, so do not touch the contacts immediately after disconnecting.
Symptoms of a faulty start relay
You can determine that the problem lies in the relay by the characteristic signs that appear in the behavior of the refrigerator. Most often, owners notice that the unit turns on, there is a loud click, the motor hums for a few seconds, and then the click is heard again and there is silence. This cycle can be repeated many times. This mode of operation indicates that the engine is trying to start, but starting device cannot distribute the current correctly or break the circuit in time.
Another clear sign is the situation when the compressor hums, but does not start, while the motor housing may heat up more than usual. In some cases, the relay may “stick” in the on position, which leads to continuous operation of the compressor without stopping, even when the temperature in the chambers has already reached the set values. This is fraught with overheating of the windings and eventual failure of the motor itself. It is also worth paying attention to extraneous sounds: rattling or crackling sounds in the back of the refrigerator often indicate mechanical destruction of the internal components of the relay.
Sometimes a malfunction manifests itself in the form of a complete lack of response to being plugged into the network. The indicators may be on, there is light in the chamber, but the compressor is silent. In this case, the relay could simply burn out, breaking the power circuit. If you observe at least one of the listed symptoms, the probability of a relay failure is more than 80%. However, for an accurate diagnosis, a visual inspection and continuity testing of the contacts is necessary.
Preparation for diagnostics and dismantling the relay
To conduct a quality test, you will need a minimum set of tools. First of all, this is a screwdriver (often a Phillips head, but sometimes a flathead one may be needed) to remove the back panel of the refrigerator. Also necessary multimeter to measure resistance and check circuit integrity. If you don't have a multimeter, you can use a simple light bulb with a socket and two wires, but this method is less accurate and requires special care when working with voltage.
The dismantling process begins by removing the protective cover at the bottom rear of the refrigerator. It is usually secured with latches or several screws. After removing the panel, you will see the compressor - a black metal tank with a cylindrical shape. A plastic box is attached to its end using a clamp or latches, to which the wires fit. This is our desired device. Carefully disconnect the terminals, having previously photographed their location, so as not to mix up the contacts during assembly.
Remove the relay from the compressor. It may be a tight fit, so rock it slightly from side to side. Be careful: the plastic housings of older relays can be brittle and crack if not handled carefully. If oxide or carbon deposits are visible on the contacts, they can be carefully cleaned, but most often a complete replacement of the assembly is required. Before checking, inspect the case for melting or swelling - this is a sure sign that the part has experienced a short circuit or overheating.
☑️ Preparing to check the relay
Visual inspection and primary diagnostics
The first stage of verification is a thorough visual analysis. Take the removed relay in your hands and carefully inspect it from all sides. The housing must not have cracks, chips or signs of thermal effects. If you see blackened plastic or smell something burning, further inspection may be unnecessary - the part definitely needs to be replaced. Inside the case there is a contact group and an opening mechanism, which must be clean.
If the relay design allows you to carefully open the case (usually it consists of two halves), look inside. Contacts should be smooth and shiny. The presence of black soot, shells or melting on the contacts indicates a violation of the sparking process. Contact group - this is the heart of the relay, and any violation of its geometry leads to unstable operation. Also check the condition of the springs and moving elements: they should move freely and return to their original position.
Pay special attention to the inductor if it is visible. The winding must be intact, without breaks or signs of overheating. Sometimes you can visually determine a break: if the coil wire has turned black or the insulation has become brittle, this is a bad sign. However, a visual inspection does not provide a 100% guarantee of serviceability, so we move on to an instrumental check. Even a seemingly ideal relay can have an internal open circuit, which is visible only to devices.
Why does the relay burn out?
A frequent cause of relay failure is not only natural wear, but also unstable voltage in the network, as well as problems with the compressor itself. If the motor is “heavy” and requires increased starting current, the relay operates with overload and quickly burns out. This can also be caused by frequent turning on and off of the refrigerator without pausing.
Checking the relay with a multimeter
The most accurate diagnostic method is to use a multimeter in resistance (Ohm) measurement mode. Switch the device to the appropriate mode and make sure that it shows zero when the probes are shorted to each other. First, check the integrity of the coil (if the relay is electromagnetic). The probes are applied to the corresponding coil contacts. The device should show a certain resistance, usually in the range from 30 to 200 ohms, depending on the model. If the screen shows “1” or “OL” (infinity), it means there is a break in the coil and the relay is not working.
Next, we check the contact group. In the initial position (the relay lies horizontally or vertically, depending on the design), the contacts can be open or closed. When voltage is applied (which is difficult to safely simulate at home, so we check the mechanics) or when the relay is turned over (for some models with a thermal relay), the contacts should change their state. By ringing the circuit, you should see the reading change from infinity to zero (or a value close to zero) and back. If the device shows constant resistance or a constant break regardless of position, the mechanism is jammed.
It is also important to check the thermal relay, which is often built into the same housing as the starting one. It is a bimetallic plate. When cold, it should conduct current (resistance is close to zero). If the multimeter shows an open circuit on a cold thermal relay, it means that it has already worked once and has not returned to its original state, or has burned out. This means that the protection has tripped due to overload, and simply replacing the relay may not help if the cause of the overheating is not eliminated.
⚠️ Attention: Resistance specifications may vary depending on the specific model Samsung. Always check the data obtained with the markings on the case or technical documentation, if available. Small deviations are acceptable, but a break or short circuit is unacceptable.
Alternative testing methods without instruments
What to do if you don’t have a multimeter at hand? There is a test method using a regular incandescent light bulb and a socket with wires. Assemble a simple circuit: one wire from the plug goes to one contact of the cartridge, the second wire from the plug goes to another contact of the cartridge, but with a break, where the relay being tested is connected in series. When power is applied (very carefully!), a working relay should close the circuit and the light will light up. However, this method is dangerous and requires skills in working with live electricity.
A safer, but less informative method is a “hearing” and vibration test. If you gently shake the relay near your ear, you should not hear the rattling of loose parts inside. You can also try to apply power to the coil (if its parameters are known and there is a power supply) to hear the characteristic click of the contacts closing. But for the average user, this method is complicated due to the need to select voltage.
The most reliable “folk” method without instruments is the elimination and replacement method. If the relay is visually intact, the contacts are clean, but the refrigerator does not start, and the compressor is working (checked directly, which is risky), then the relay is replaced with a known good one. If after replacement the equipment started working, then the problem was in the relay. This method is often used by service technicians who carry with them a set of running spare parts.
Table of faults and solutions
To systematize the data obtained and simplify diagnostics, we will create a summary table. It will help you quickly compare symptoms, measurement results and necessary actions. Remember that a comprehensive assessment of the condition of all nodes gives a more accurate result than checking only one parameter.
| Symptom | Multimeter readings | Visual sign | Solution |
|---|---|---|---|
| Clicks, not starts | Breakage of coil or contacts | No traces | Replacement of relay |
| Buzzes, gets hot | Resistance is normal | Case melting | Replacing the relay and checking the compressor |
| Does not respond | Open circuit | Blackening of contacts | Replacing the relay |
| Works without stopping | Closing contacts | Sticking of the mechanism | Replacing the relay |
Analyzing the table, you can see that in most cases the solution is to replace the part. Relay repairs (cleaning contacts, straightening plates) are temporary and do not guarantee reliable operation in the future. Modern relays Samsung are often produced in sealed or difficult to disassemble housings, which makes their repair economically impractical. It is easier and safer to install a new original component.
If after replacing the relay the problem persists (the compressor hums, but does not start), this may indicate a more serious breakdown - an interturn short circuit in the motor windings or jamming of the piston group. In this case, simply replacing the relay will not help, and the intervention of a professional technician with equipment will be required to overhaul the compressor or replace it.
Replacement and final assembly
The process of installing a new relay is the reverse of the dismantling process. Make sure the new device has identical markings and pin shapes. Slide the relay onto the compressor rod until it clicks or makes a tight fit. Connect the wires according to the photo or color code you took earlier. Usually the blue wire goes to one contact, black or brown to the other, but it is better to double-check the circuit.
After connecting all the wires, secure the relay with a fixing bracket or strip, if provided by the design. Make sure the wires are not pinched or touching hot parts of the compressor. Only after carefully checking all connections can the protective rear panel be reinstalled. Tighten the screws or snap the latches.
Plug in the refrigerator. In the first minutes of work, listen to the sounds. The compressor should start with a characteristic hum, then the relay should click (disconnect the starting winding), and the motor will continue to run smoothly. If the startup was successful, let the refrigerator operate for about 30-40 minutes without loading food to make sure that the operation is stable and cold appears in the chambers.
How to extend the life of the new relay?
To ensure that the new relay lasts a long time, ensure good ventilation in the back of the refrigerator. Do not move the unit close to the wall, leave a gap of at least 10 cm. Regularly clean the condenser (black grille at the back) of dust, since overheating of the compressor is the main enemy of the starting equipment.
Is it possible to repair a burnt-out relay yourself?
Theoretically, if the relay is dismountable and the only problem is the burnt contacts; they can be cleaned with fine sandpaper. However, the resource for such repairs is extremely short. The contacts will burn out again after a few switching cycles. In addition, violation of the factory calibration of the springs can lead to incorrect operating time of the starting winding, which is dangerous for the compressor.
Why does the relay heat up during operation?
Slight heating of the relay body is acceptable, since current passes through it. However, if the relay becomes hot enough to melt plastic or cannot be touched by hand, this is a sign of a malfunction. Either a relay with unsuitable characteristics has been selected, or the compressor consumes too much current due to wear.
Where to buy an original relay for Samsung?
Original spare parts are best purchased from authorized Samsung service centers or from large suppliers of spare parts for household appliances with a good reputation. When purchasing, pay attention to the presence of holograms and the quality of packaging. Cheap Chinese analogues can work, but their service life is often several times less than the original.
What to do if the new relay does not fit the connector?
Sometimes manufacturers change the design of the connectors. If the relay matches the electrical parameters and fits on the compressor, but the wire connector does not match, you can carefully resolder the wires or use adapter terminals. The main thing is to maintain the polarity and reliability of the connection. Do not twist the wires just like that, use soldering or crimping.
How often do you need to change the starting relay?
The starting relay does not have strict replacement regulations. It changes only after a breakdown. Its service life depends on the quality of electricity in the network, the frequency of voltage surges and the intensity of use of the refrigerator. On average, a high-quality relay lasts 5-10 years, but can fail even earlier under unfavorable conditions.