AMI I 200 Problem

Guys: I have a 1958 AMI I 200 jukebox and it has a problem with the
'pin pusher' mechanism. Whenever I choose a record, it will push the
pins for the following record, instead. For example: I choose D4 and
it will push the pins for D6 or I choose H16 and it will push the pins
for H18, etc. Happens every time and was like this when I got the
jukebox. I have read the manual but I am new to jukeboxes and cannot
fathom it out. Any help appreciated. Thanks.....