Thanks, I had a good lead in the source of the problem.

I'm not an electronic expert but I can fix things and I really like challenges like that.
With help from boards like this it's even easier when I get to talk to experts like you! Someone who knows his stuffs

I played for the first time with the owner after the repair. Fun game.
I secure the cables on the board with hot glue making sure to let the connections exposed if I need to get back for another repair. That's not pretty, but it makes the game run and that was the goal. The owner is happy, so am I!