I have a PRS Alpha bot that was working fine the last time I used it, When I turned it on a few day ago I got the error message to reset drivers. After running through checks of the remote stop/reset switch and wiring to the control board terminals, aux, and contactors I find that the 3A fuse is open. Upon replacing the 3A fuse it immediately blew again. I can not visually see a short anywhere and am at a loss, has anyone else had a similar problem, and if so, how did you solve it? thanks