Location 27 is in the CCC programming, this is accessable via the service switch in the service position.
Please see your jukebox manual it will show you how to do this.
With regards to your gripper bow, I suggest that you remove it and fully strip it down and clean all the parts in warm soapy water, inspect all the parts for any wear and replace if necessary.
Regards
Alan
Alan Hood
ami-man
UK