There were no bad parts, just bad connections. I ended up resoldering all the feed thru eyelets, then flipping the board and removing the solder with a sucker, then resoldering them with much less solder. They all look pretty clean now. I know other companies that used the eyelet method had reliability problems. For some reason the solder cracks around the eyelets, probably related to different coefficients of thermal expansion.
That's from an email my tech Dave Brown sent me. In a different email, he distinguishes between what he calls 'feed thru eyelet' boards and 'plated thru' ones. The Victor evidently uses the former. I am completely ignorant of the meanings of the 2 terms--am just passing on others' wisdom as I received it.