If your refrigerator doesn’t start when connected to power, the issue might be related to the compressor or associated circuits. Below, we explain the possible causes and how to diagnose them effectively:
1. Low Supply Voltage
Insufficient voltage prevents the compressor from receiving the energy needed to start.
Diagnosis:
- Use a multimeter set to AC voltage to check if the power supply is stable and meets the refrigerator’s requirements.
2. Faulty Electrical Connections
Damaged cables or loose connections can disrupt power delivery to the compressor.
Diagnosis:
- Visually inspect the cables and connections leading to the compressor. Repair or replace any damaged components.
3. Damaged Compressor Coils
Open or shorted compressor coils will prevent proper operation.
Diagnosis:
- Use a multimeter set to ohms:
- For conventional compressors, the readings should neither be zero nor infinite.
- For inverter compressors, the resistance values between pins should be similar.
4. Faulty Start Relay (Conventional Refrigerators)
The start relay powers an auxiliary coil to help the compressor start. A defective relay will prevent this.
Diagnosis:
- Replace the relay and test the compressor again.
5. Defective Start Capacitor (Conventional Refrigerators)
A faulty capacitor can stop the compressor from starting even if the relay is functional.
Diagnosis:
- Use a multimeter set to capacitance to check the capacitor’s condition. Replace it if necessary.
6. Thermal Protector or “Click-On” Malfunction
This device disconnects the compressor during overheating or excessive current draw. If defective, it may block the compressor from starting.
Diagnosis:
- Check for continuity between the thermal protector’s terminals. Replace it if there is no continuity.
7. Issues with the Electronic Control Board
In refrigerators with electronic control boards, faults in relays or defrost systems can interrupt power delivery to the compressor.
Diagnosis:
- Inspect the board for damaged or burned components and repair or replace them as needed.
8. Inverter Module Problems
In inverter refrigerators, a defective module supplying three-phase current to the compressor can cause failure.
Diagnosis:
- Test the inverter module using a multimeter set to diode mode. Check that the U, V, and W outputs have consistent readings.
9. Power Supply Issues (PFC Circuit)
If the circuit converting AC to DC power is defective, the inverter compressor won’t receive adequate voltage.
Diagnosis:
- Use a multimeter to check the board’s power supply. Repair or replace any faulty components.
