No power, no crank, no start

A few weeks ago, the wire going from the starter (I'm guessing) to the fuse box under the hood burned in half causing the car to not crank. I replaced it; the car ran fine then didn't. Now when key is inserted and turned to the "on" position everything on dash and headlamps come on as normal. But when the key is turned to the "start/crank" position everything on dash goes off and nothing happens. The car doesn't crank. It doesn't make the tick sound as if the battery is drained or nothing. It's almost like having a light switch on and flipping it off. I've followed wires to starter, and all seems okay. I replaced starter because when I had it tested the guy said it was definitely shot. Nothing worked.