Why does my Samsung MW5380W timer start but there is no heat?
- JjohnsonrhondaAug 20, 2025
If the timer on your Samsung Microwave Oven counts down, but there's no heat, even though the oven lamp and fan motor are running, several factors could be responsible. There might be off-alignment of the latch switches, or an open or loose connection in the high voltage circuit, especially the magnetron filament circuit. Also, defective high voltage components like the H.V.Transformer, H.V.Capacitor, H.V.Diode, or Magnetron could be the reason. Other potential causes include open or loose wiring of the power relay, a defective primary latch switch, or a defective power relay or Ass'y PCB. You should adjust the door and latch switches and check the high voltage components; replace them if defective. Replacing the PCB main may also resolve the problem.