Rivet under handle is loose
When you take the screw completely out and pull the handle out, usually the wires need to be unhooked under the switch plate, you will see the top of a rivet head when looking down the hole in the bag housing. The other side of the rivet is inside the bag compartment and appears as a rectangular head at the very top, right in the middle. To tighten this rivet is not real easy. We used a large shaft out of an old washing machine. You need a shaft that is 3/4" to 1". Tighten this shaft in a vise, and insert the entire machine upside down over the shaft. The shaft goes where the handle originally went. Do not get the handle wires pinched between this shaft and the rivet head. While one person holds machine vertically, upside down, another person repeatedly hits the rectangular rivet head with a 1/4" punch and hammer. You have to smack it hard and around 20 times or so. After removing the bag housing off of the large shaft you will see that the head down inside has flattened out. Sometimes the screw itself gets worn out, from being loose and rocking back and forth you will see grooves worn into the screw.