I've worked on many ATS devices...on gensets in the MW class, but the electronic hardware for the ATS is the same regardless of the main switch rating, generally speaking.
I read your thread over on the other site and this stands out to me:
"In situations like this I clean and torque every single connection in the whole rig, then resume testing as that at least ensures your wiring ends are in good contact."
When I was a young pup I always wanted to know WHY the problem occured. As I grew older and wiser
I was simply satisfied to get the gear back online. I learned that by loosening and re-tightening -all- of the connections (as stated above) it sometimes 'fixes' things.
Part of the problem is that crap forms on the connections and you just can't see it. By mechanically moving the connection, you break through the invisible film and reestablish the electrical connections.
Helpful hint: NEVER remove the wires from more than one terminal at a time since 'bad things' can happen if you make a mistake. Loosen the screw, remove the wire(s), check the termination, reinsert and carefully re-tighten. Work slowly, carefully and methodically. It's not a race (unless people are dying in the operating room
I'd also suggest having a good light and magnifying glass with you so you can REALLY check everything. I have caught wire/connector failures that a person wouldn't have seen otherwise.
I've spent most of the day reviewing the manual and schematics in depth, and insofar as you have replaced the mobo and the daughterboards with known good boards, I'm thinking the loosen/tighten process holds the most promise...that, and the confirmation that the aux switches are correctly installed.
BTW, post the EricWood #23 documents here...registrations are manual so it might take a day or two for me to be able to see those. Thx...--
Nothing makes an American want to do something more than telling them they can't.