Do you have a forward reverse handle on the right hand side of the apron that moves the bottom rod to operate a switch? the 'start' button may just prime it.
edit: on a lot of these machines the emergency stop button gets it ready and puts power on the circuits but forward / reverse / off is selected by that lever on the apron. The go button on the headstock is just a jogging button not a master on.
Edited By Bazyle on 05/12/2015 19:43:39