Chuck,
It's been a LONG time since I fiddled with one of these, but your experience is not unique. Those "102" reverse unit/motor driver boards aren't well-behaved. I wish I could remember more, but a few thoughts off the top of my head:
1) There was one type of transformer I found that dramatically improved the function of the board. It was either old-school sine wave, or the newer chopped-wave style. I can't remember which it was, but it was probably the sine wave-type.
2) There was also a "rhythm" to getting the reverse unit to function predictably, and it had to do with timing and whether the direction button was used, or whether voltage was lower and raised to cycle it. Again, I can't remember which it was.
3) I think the only place that board was used was on the non-TMCC motorized units. I worked on a later version one time (I think it was the 6-18474 Army which had the same board) and noticed it had an extra component soldered to the backside. Can't remember what the component was (but it was basic, like a resistor, diode or cap) but I noticed that the reverse function worked much better so I'm guessing that's the band-aid.
Sorry I can't remember more, but you're not alone on this one!
TRW
