Samsung Microwave MS1440BB No heat

This door interlock microswitch detects when the microwave door is fully closed and allows the unit to run only under safe conditions. Replacing a worn switch restores reliable starting and consistent operation tied to the door latch.

• Monitors the door-latch position and completes the safety interlock circuit when the door is closed
• Helps prevent operation with the door open
• Common symptoms: microwave won't start or stops when the door is moved; requires pushing/jiggling the door to run
• Contributes to "runs but no heat" or light/fan behavior that changes as the door is opened/closed

• Unplug the microwave before service; internal high-voltage components can retain a dangerous charge
• Access the switch at the door-latch assembly; transfer wires one at a time to the new switch to maintain correct positions
• Ensure the actuator aligns with the door latch and that the switch clicks freely when opening/closing the door
• After reassembly, test with a microwave-safe cup of water to ensure proper operation