Roper Electric Dryer REX6634PQ0 - hums Does not start

Roper Electric Dryer model – REX6634PQ0 - hums when switched on, drum does not move. If we keep dryer plugged in and EVEN when dryer timer knob is in OFF position, we hear something running – like a running belt or fan etc. While plugged in, when we open the door, we see a light/filament burning inside the dryer and it gets warm as well.

Pressing the start button has no effect whatsoever.

Opened the top panel of the Dryer and see that the belt looks OK, it is tight and am able to rotate drum. Now, should I look at motor or look at thermal fuse etc?