Thanks John/TRW for your responses.
This is Lionel 6-28273 CSX - Cab 3329. It is from an Intermodal Set. I bought the engine a few months ago (not the set) brand new in the box. Circa 2007. Sorry, I don't have the set #.
It worked well briefly and very shortly thereafter, the radio board went and I replaced it. All was fine except I lost some sounds. Two for sure are the Brake release sounds when I use my Legacy controller to change direction and brake squeal is also gone. Runs and sounds great otherwise. I can live with this .....I am just curious as to why this happened. ? I've included pics as requested (the CS markings on the chips are mine). I did pull the chips (with chip puller) and reseated but to no avail. Early Legacy 5.5. I replaced the smoke resistor with an 8 ohm one. It also has that annoying issue of the smoke unit not shutting off when the engine is shut down....common as I understand it to this era of early Legacy units.
I did do a full reset, code AUX 1 - 2, also to no avail.
This unit is road specific and the boards are not available from Lionel. Be happy to buy a used one or another SD 40-2 board....road specific not necessary if anyone might have one.