Gajaman,
Replace and recrimp all of your molex connectors. I know it sounds extreme, but it will save you from an even bigger head ache down the line. I guarantee you that if the guy was this lazy with the rectifier board, then he was lazy with the rest of his repairs on this machine. People dont like to do the whole recrimp thing and pass it off. But, most pinball problems start at the connectors.
Hawkypro