no 3g connection

hey guys
i'm a newbie here. I was wondering if anybody could help me out with this. i have an lg optimus one. its unlocked.it was originally locked to telus but i now use it with fido.i can't get 3g on it . in the manage running apps it says its not even running. any idea why. i have a data plan, but can only use the interneton wifi, which is no good to me when im away from home.