AMI I-200 not selecting record 16 and above

I got finally the AMI I-200 with pushbuttons almost up and running.
The remaining problem is selections from 16 and up will play the respective record number 16 only.
Pulse generator checked on connections all good.
Pulse converter cleaned looks fine (but you never know).
All letter selections work, numbers 1 - 16 also no issue.
Checked the pulse selector of the numbers, looks like at the correct spot on the printed plate.
Capacitors 2x 100mFd have been replaced as well.
Any advice is very welcome.
thanks, Rick

Hi Rick,

just a guess: If the buttons are connectet in series and button #16 does make bad contact to the next one, then no selection upwards would work.

Regards - Hildegard