Why does the electric starter quit working on scooter?

There are 5 possible reasons why the starter quit working on the scooter. First, the battery was bad, second, the starter switch was bad, third, the solenoid was bad, fourth, the the starter motor was bad, and fifth, there was a bad wire. I found another reason, which was the one that fixed my scooters problem and that was the brake switch had gone out. Without the brake switch working the automatic starter won't engage.