Hi, I have a Taiyo Electric Top Gun pachinko machine that has a shooter problem. It feels like it has a bad bearing. It won't snap back to (what I call the zero position).

The knob has no spring tension at the zero position. It feels like it's grinding, and it squeeks.

I need to find out how to remove the knob so I can see what's worn out, or if something is jammed inside.

I was told that there is a screw on the bottom that allows you to remove the knob, but I don't see any screws.

The shooter fires the balls normally, but it doesn't feel right when you turn it to shoot.

Please help.

Thanks