Display shows dO or a door icon and an alarm beeps even when the door appears closed.

Safety first: Unplug the unit before accessing the door switch area.

• Check door alignment: Ensure the door is level and fully closing. Adjust leveling feet so the door naturally swings closed.
• Inspect gasket: Look for gaps or twists in the door gasket that prevent full closure. Warm and reshape the gasket with a hair dryer if needed (do not overheat).
• Locate door switch: On many NEEDONE models, a magnetic reed switch is hidden in the cabinet frame, and a magnet is embedded in the door. Look for a small plastic housing or mark on the frame.
• Test magnet: With the unit powered, hold a strong magnet over the frame switch area. If the alarm stops, the door magnet is weak or misaligned.
• Replace parts: Replace the door magnet or reed switch assembly if they fail to signal door closure. Ensure correct positioning.