Can't get TITO to work in 1 of my 2 BB2 cabinets

[Parsonsaj]

I am only using TITO for free play... don't have a printer on either cabinet.

The cabinet that is a straight video cabinet works fine as long as I make all the required setup changes during install.

My other cabinet is a dedicated Alice reel cabinet. No matter what I do I can't get it to communicate with the COMM port (either of them). The Tito has a LED for power from the USB connection, but never gets the other LED to light up. I've verified that all the jumpers are set consistently with the working cabinet. I've swapped boards between the cabinets and the good cabinet works fine with the same board that's not working in the reel cabinet. I'd tried both tito@home and bettor boards and both behave the same. I've swapped CPU and backplane modules and the behavior does not change. The jurisdiction chip does allow progressive bonus and I have it enabled.

I really thought the backplane swap was going to resolve this issue. What are the odds that I could have 2 BB2 (blue) backplanes that had comm port problems?   

Any help greatly appreciated... my wife would really like to have that $200 cash I keep in this game but I told her she can't have it until the tito works!