Refrigerator displays SY CF; unit may not respond to controls or may not cool correctly.

Safety first: Always disconnect power before removing rear covers or touching control boards.

Step 1: Hard reset

• Unplug the refrigerator or switch off the breaker for at least 10 minutes.
• Restore power and observe if SY CF reappears within a few minutes of operation.

Step 2: Inspect main control board

• Access the main control board at the rear of the refrigerator (behind a metal or plastic cover).
• Check for visible damage: burnt spots, cracked solder joints, or swollen capacitors.
• Ensure the board is firmly mounted and not flexing or contacting the cabinet.

Step 3: Check supply voltage

• With power on and using a multimeter (only if you are trained and comfortable working with live circuits), verify that the board is receiving proper line voltage at the input connector.
• If supply voltage is unstable or low, the issue may be with the household circuit rather than the refrigerator.

Step 4: Replace main control board

• If SY CF persists and no external wiring issues are found, the main control board is typically replaced as a complete assembly.
• Disconnect power, label and remove all connectors, remove mounting screws, and install the new board, transferring any jumpers or settings as per the service sheet.

When to call a technician: Because this fault involves live voltage checks and board-level diagnosis, professional service is recommended for most homeowners.