Quoted from Hi-Fi:I looked at the schematic and “I 6” (65-A4J2-14) has most of these features so I thought I was on to something. However, the right flipper and the tilt still work?
You are onto something.
All those switches on "I6" that aren't working come from MPU connector J2 to the playfield. The tilt and right flipper button on "I6" come from MPU connector J3 to the cabinet.
So you likely have a bad connection at MPU J2 pin 14 that needs to be reterminated with a new crimp terminal.