At a more complete look... all the 180 resistors are the new pattern on board 12, so I believe it's just a manufacturing difference (unless they are all wrong!?!). I looked as closely as I could for any 'bridging' inside the sockets and didn't really see anything amiss, though I'm not sure what exactly I would find if it were 'bridged' in there.
I am also in joyous receipt of 4 more Lynx express kits today compliments of the J team in FL (Thanks guys), so I now have spare parts galore if it's time to start pulling and replacing things on board 12. I'm not (yet) an electronics guru, so testing via DVOM etc is beyond my current knowledge level... and I wouldn't know what I was looking for anyway... so I ask:
Is it time to start pulling and replacing components? If so, what's the best order to move in? I don't mind buying a few replacement parts if necessary, I just am really reluctant to scrap the whole board. Given that the chips all work in board 11, I have to believe it's either my error, or a minor component failure.
Thanks also to everyone who's offered suggestions so far. I didn't mean to tie up so much collective brainpower on my piddly problem. I'm at a loss here and I really do appreciate all the help.