I tried to add a double pole switch to my 3520B so I didn't have to keep plugging it in and pulling the plug out at the end of my work session. I didnt' come on when I threw the new switch, that is, the lcd panel on the headstock did not light up. Nothing seemed wrong with the switch, but I took the switch out of the line and it still won't come on. I tried the red reset and the green start buttons on the back to no success. I opened it up and smelled the wiring, but there was no burned smell. thoughts?