GRJ, the diodes are 200v 1A (1N4003, same as what you used), does that make the HCT chip more suspect? And there is a path directly to the HCT's Vcc when connecting D2 to R11 and D2 is track voltage.
Very Scary, I know, but this has gotten me to print out the schematic and look around a little. Trying to gain better understanding here myself.