Success!! I am posting here for others that are still struggling. I picked my SignaLink up to check the physical connections and I had thought I might do continuity checks on all the cables - that is when I heard something rattling about inside the unit. Yep, you guessed it, the jumper had come loose. Once re-installed, I was on the air working stations in no time. Things I did learn in the process. I can key up the transmit audio via the CAT control but that is not how my setup is designed to work. I use the VOX setting to "key" the TS-2000. In fact, I can disable CAT control all together and provided I tune the frequencies WSJT-X still is able to make contacts with the SignaLink sound card unaware of the underlying radio. If you are still having trouble, might I suggest you focus on the SignaLink and eliminate the TS-2000 CAT control from the equation until you have the SignaLink working.