You should measure voltages at J115 between paired conductors (e.g., between green and white/green); it sounds like you are measuring to ground, which will give confusing results. If you measure between paired conductors you may find that you have zero volts across the violet and white/violet wires. If that's the case then I'd check for a break in continuity between the 9-pin connector at the transformer and the connector for J115, particularly the violet and white/violet.