A compressor that isn't working is a serious problem because it's the heart of your refrigerator's cooling system. Without it, your fridge cannot circulate refrigerant to remove heat. The cause can range from a simple electrical component failure to a major mechanical breakdown .
### The First Step: Listen and Look
Before you do anything else, the most important step is to determine if the compressor is actually trying to start.
**1. Listen for the Hum:**
Plug the refrigerator in and listen near the bottom back panel. A functioning compressor typically makes a low humming or vibrating sound. If you hear **absolutely nothing**, the compressor is not receiving power or has failed internally .
- If you hear a **clicking sound followed by a hum that stops** after a few seconds, the compressor is trying to start but is failing. This often points to a problem with the start relay or overload protector .
**2. Check the Condenser Fan:**
Pull the refrigerator away from the wall and listen for the fan near the compressor. This fan cools the compressor and condenser coils. If it is not running, the compressor can overheat and shut down or fail .
### Common Reasons for Compressor Failure
If the compressor is silent or failing to start, the problem is likely one of the following.
#### 1. A Failed Start Relay or Overload Protector
This is the most common electrical failure . The start relay gives the compressor the initial jolt of power it needs to start, and the overload protector shuts it down if it overheats. If either of these components fails, the compressor will not run.
- **Signs:** A burning smell coming from the compressor area is a strong indicator that the start relay has burnt out . The compressor may click but fail to start.
#### 2. Demo or Cooling Off Mode Activated
Some Samsung refrigerators have a "Cooling Off" or "Demo" mode used in retail stores. In this mode, the lights and display work, but the compressor is disabled to save energy, meaning no cooling occurs .
- **Signs:** The display might show "OF OF," "O FF," or "OFF" . Deactivating this mode requires a specific button combination found in your user manual .
#### 3. Dirty Condenser Coils
Over time, dust and pet hair can coat the condenser coils (located at the back or bottom of the fridge) . This prevents them from dissipating heat, causing the compressor to overheat and either shut down or fail completely .
- **Signs:** The refrigerator may run continuously or stop completely. Cleaning the coils is a simple but essential maintenance task .
#### 4. A Faulty Control Board (PCB)
The main control board sends power and instructions to the compressor. If the board fails, it may not signal the compressor to start .
- **Signs:** The refrigerator may cool for a while and then stop, only to restart after a power cycle. Older models can develop bad capacitors on the control board, causing this intermittent behavior .
#### 5. A "Locked" Compressor (Internal Failure)
If the compressor itself is mechanically seized, it cannot start. This is a sealed system failure and is a more serious issue .
- **Signs:** The compressor may make a loud humming sound as it tries to start, which is often followed by the overload protector clicking it off . This can happen if the unit was moved improperly or if there were power fluctuations .
#### 6. A Refrigerant Leak
The compressor pumps refrigerant through the sealed system. If there is a leak, the system will lose pressure, and the compressor may run but fail to cool, or it may stop running altogether .
- **Signs:** This issue requires a licensed technician to locate the leak, repair it, and recharge the system with refrigerant . Refrigerant work is not a DIY job.
### Professional Diagnosis
If the compressor is silent, if you smell burning near the back, or if you have confirmed it is not the start relay or control board, it is time to call a professional . Sealed system repairs, including compressor replacement or refrigerant handling, require specialized tools and training . It is also safer to leave diagnosing electrical issues, like a faulty main board or relay, to a technician .