Rockola GP160, selection is made and then stops

Most of the jukebox works fine , however on some selections it acts as if it wants to go find the record and then stops(the wheel holding the records goes to take off and then stops after about 2 sec.). However if the same selection that did'nt work is selected while another is playing, the box will infact go and select it after the previous is finished. If this is hard to understand I am sorry, but if anyone can help me I am all ears.

There is a sense ring or plate on the selection unit that detects if any pins are still out. If this is loose or bent, it may sense the absence of selected pins when a pin is in fact selected.

On some units, a problem in the credit unit can also cause this.