Okay, I had time to take a look this morning. Indeed, the power wires were under the board. Interestingly the board was angled up a little bit until the heat sink was touching one of the capacitors. In my case there was some heat sink paste on the capacitor. I wonder if the contact between the heat sink and the cap could have contributed to the problem. 
Anyway, I rerouted the wires over the top, didn't disconnect anything.
I tried it at first on the Christmas tree loop with a z4000 and it would power up, the whistle worked, but cycling the power did not result in the engine moving.
After that I took it downstairs and fired it up with the dcs. Solid 10 around the loop, but I didn't check it before. Did a factory reset and brought it back to the tree loop. Low and behold it suddenly worked in conventional!! I will have to reload it into the remote later, and see if it responds in conventional without being reset.
Anyway this is the first time this thing has worked in conventional for years. Thanks for the help!
