hall effect sensor as a rpm mesauerment device

The led should follow the state of the button. Perhaps the input is floating, check to make sure that the switch is connected to pin 7. If you have a voltmeter, check that the voltage is 5 volts on pin 7 when the switch is not pressed and 0 volts when pressed.

Also, are you sure your sketch has been sent to the board, as I recall on mine. the default sketch just flashes the led.