To the other posters with suggestions about broken traces or bad relays, I appreciate the advice, but the board looks good. Nothing I can see that would indicate a component failed, or anything overheated which might lead to a ruined relay or burnt open trace. And it's all put together well. Plus they used conformal coating on the board which is not fun to test around or remove.
It's not my system but a friends and there's a time issue...so I haven't tried to pull the board out of the case to examine the backside.
But if AZPete has any definitive advice about a certain component or a bad trace I'll certainly attempt a repair here in Mexico rather than letting it be shipped back and forth.