I brought my NKP 8100 and NKP 765 to a friends DCC layout today, he ran and programmed them to their numbers and everything was fine. I came home to my DC layout, put them on the tracks and neither of them will not move or with they light up. 8100 however does play the prime mover sound only. I have not had an issue with this before as I worked at a club and have had my other engines numbered and they work fine on my layout. Any help with be awesome!
The usual suspect is your friend programmed your locomotives using a DCC systems that automatically programs the decoder to run only using DCC.
If you find CV 29 = 34. Then program CV 29 = 38 and you can use either DCC or DC with address 8100 and 765.