Scientist, did you try rocking the bike when the key is in the "on" position and it's in gear before starting it to see if you get the tach sweep and the indicator lights to come on? If so, you have the same problem I do. I did all of the stuff that you did (except soldering the wires, I cleaned the crap out of the connectors and dielectric greased them). I finally decided to bring it to the dealer. Triumph told them that they needed to start replacing parts (Speedo and tach, then if that didn't work ECU). I protested. The dealer had a 2005 trade-in on the floor. They tried the speedo from it on mine. That was the fix. I am currently waiting on a new speedo from the UK. Gotta love the piss-poor wait times on parts for these bikes.....