John the locomotive that I have has a 691R2LCC08 R2LC / R4LC / RADIO RECEIVER (C08 CODE) and a 691RSPRA00 RAILSOUNDS 4E / SPSF SD-40T-2 #8521 and a 691RSPRA00 RAILSOUNDS POWER BOARD / UNIVERSAL they are all attached to the Motherboard. The Railsounds boards in no longer available from Lionel. All I did was remove them and clean them and reinstall them and that corrected my issues with all the sounds.
Gary