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. Pin StarterThese are used in toy music boxes, where the pin blocks the air brake. When pulled, the music plays, when pushed, the music stops. If the box does not play, make sure that the pin blocks the air brake and that when it is pulled, it releases the air brake. The pin should not be too long and if it is, it may need to be filed down. If it won抰 stop playing, then adjust the position of the movement and make sure that the pin is not too short.