hey guys. I've got a yale GDP210DB that wont start and E_CON keeps coming up on the display. I'm assuming it a code of some sort but i cant figure out why or where it came from. I pulled the lift in the other day and it was running fine. I changed the oil,air system governor and pulled the seat off to get reupholstered. now its all back together and wont start. any help or advise would be greatly appreciated. thanks