i push the start button and heres what happens. green sensing light comes on and the red door lock light comes on. there is a buzzing noise for a few seconds then the door lock light goes off, sensing light stays on. then a few seconds later red door lock light comes on but blinks this time, sensing light is still on. and there it sits. the tech sheet has been removed so i dont even know where to begin. any suggestions are appreciated, thank you.