Hi Guys. I bought my son a DCC Mallard A4 by Hornby for Christmas. I assumed it was like most American locos, that run on DC and DCC by default. I was wrong. The Mallard runs well on DCC, but is dead on mu son’s DC set.

The Mallard manual says to add bit 4 to CV 29 to get it to respond in DC. I have a Digitrax DCS50 with the little booster board, but when I tried to program per the instructions, the DCS 50 read “d nA” which is an error code that says the DCS50 cannot detect the decoder. I contacted Hornby USA, but they don’t seem to understand that the programmer cannot talk to the decoder.

Can you folks help me solve this problem? The DCS50 manual does not list Hornby as one of its common manufacturers, and has a 2004 date on the manual. I suspect there must be a way to get the DCS50 to “talk” with the Hornby decoder. I likely bought my Digitrax system from you guys, but it would have been a very long time ago. But I would ask you anyway; you are the top of the line decoder specialists in the industry as far as I’m concerned.

Respectfully, Chris M.

Firstly, thank you for the kind words. We think we have some really great people here at Tony's too.

The DCS50 only outputs a signal on the Program Track when you press enter. It is not there long enough for the sound unit in your engine to start up and respond, so you will get the "no decoder" message. Assuming you want to use the short engine address (default is 3) and you want analog (DC) enabled, CV29=6.

Use the Program on Main function of your DCS50, preferably on an isolated piece of track to avoid accidentally programming another engine. Refer to your manual, but you are going to place the engine on normal powered track and then use the Program on Main mode to change CV29. If you select the correct mode, the programming icon should be Po. I assume you did NOT change the engine default address from 3, so enter 03 as the engine address when asked, and then select CV29, set the data to 06, and press enter. You can't read the CV with Po, but it should program and 06 should enable DC operation and leave the selected address as short which will still be 03. The engine should then work on DC or DCC address 3.