Thermostat
Reads or limits temperature. A failed one can stop the heat or let it run too hot.
High-voltage capacitor
A motor that hums but won't start often needs a new capacitor.
Door micro-switch
Door, lid and control switches stop a cycle when they fail.
1ThermostatDE47-20032B
2Capacitor2501-001016
3Micro-switch3405-001033Part numbers come from the Sears PartsDirect parts list for the Samsung MS1040BB/XAA (view the list), checked November 15, 2026. Amazon buttons open a search for the part number; we may earn a commission.
Where the model number is
Open the door: the label is on the frame. Over-the-range models: sometimes behind the vent grille.