Use a multimeter to check for continuity between Terminal 1 and Terminal 2 during defrost mode. If there is no continuity, the timer is faulty. Refrigerator Defrost Timer: Working, Testing & Connections
Terminal 1 is always hot. Inside the timer, a cam connects Terminal 1 to Terminal 3 (Compressor ON). When the timer reaches defrost, the cam connects Terminal 1 to an internal heater (or nothing on 3-wire), stopping the compressor. samsung refrigerator defrost timer wiring diagram
Standard Samsung defrost timers generally follow a universal 4-pin configuration. Tracing these connections using a Samsung Wiring Diagram can help identify each terminal’s role: Use a multimeter to check for continuity between
Most Samsung-compatible mechanical timers (such as the Sankyo TMDE series) utilize a 4-pin configuration: Inside the timer, a cam connects Terminal 1
Instead, they use a main control board that runs defrost cycles based on sensor input (thermistors) and compressor run time.
You will need a multimeter (set to Ohms or Continuity) and a screwdriver.