Actually, Yesterday I purged the system and reprogrammed it and it ran fine. When it failed it was running for about 4 hours so it might have been an overheat problem. I will see what happens and report back.

I just recently purchased the N scale version, with sound. I programend the cab # only and the unit worked and sounded perfectly for about 4 hours. After that it ceased to respond to my Digitrax DT402d throttle. I re programed it again and still would not respond. Does anyone out there have any Ideas?  I will be purging the system and try to see if it runs again. 
This happend during our clubs open house with several cabs programed into the Super Chief system.
Once again, any thoughts out there?