Refrigerator shows E6 and may not respond correctly to temperature changes; compressor may run continuously or not at all.

Safety first: Disconnect the appliance from mains before accessing the control board compartment.

Steps:

• 1. Power cycle: Unplug the refrigerator for at least 10 minutes to allow capacitors to discharge. Plug back in and observe if E6 reappears.
• 2. Check supply voltage: Use a multimeter to verify that the wall outlet provides stable voltage within the range specified on the rating plate (typically 220–240 V AC in EU). Avoid using undersized extension cords or multi-plug adapters.
• 3. Access main PCB: On many Siemens models, the main board is located at the rear behind a metal or plastic cover near the compressor. Remove the cover screws and inspect the board.
• 4. Visual inspection: Look for burnt components, bulging capacitors, or darkened areas. Check for loose connectors or signs of moisture ingress.
• 5. Reseat connectors: One by one, unplug and firmly reconnect each harness to the board, ensuring correct orientation.
• 6. Replace board if necessary: If E6 persists and no external component faults are found, the main control board is likely defective and should be replaced with the exact Siemens part number.

Warning: Board-level repairs (soldering components) should only be performed by electronics professionals; otherwise, replace the entire PCB.