"Did you measure continuity from each ground (mounting holes) to B-". With holes drilled lost continuity to mounting hole and B-. After filling mounting hole with solder, continuity returned from all mounting holes to B-. "Did you measure continuity from B- to the the atty ground connection at the atty?" - yes, has continuity. "Did you measure from the negative atty pad at the board to the negative connection at the atty?" -yes has continuity. Soldered 1 ohm high watt resistor to output, no atty used, very positive connection. "Did the board work prior to you drilling the holes bigger?" - never tested prior to drilling. I did previously , drill out a 75C successfully. Assumed this would work.