When the pressure is released on the metal stick, a spring pushes the spring up and moves a connected wire down, which releases an air brake and causes the music box to play. These are the types of music box movements you need to be aware of to repair it. You should try changing the angle of the spring with pliers. You may have to adjust it quite a bit, up and down, left and right, depending on if the music starts, doesn抰 start, or starts but won抰 stop. You can also pull the metal stick, which may be caught on something or slightly bent. If bent, it should be replaced. Button StarterWhen a button is pushed on the box, a metal plate moves the starter mechanism, which releases a latch from the wheel of the cylinder in music boxes. This releases the air brake that allows the box to play. In these, check to make sure that the button mechanism does not have a loose nut, and if it does, tighten it. This will hopefully allow it to connect with the metal plate to start the music. You can also adjust the plate and move it closer to the starter button.