New N-Scale Atlas U23B with a AN12A0 decoder will not move in either direction until speed step 50, regardless of CV2s setting. After it starts it is a very good performer at slow and higher speeds. I have tried CV2=2, 20, 30, 40, and 100 regardless of the setting it starts at SS50. I'm using NCE for my DCC control.
Are you reading back to validate that CV is getting set to what you think it is? CV2 at 100 should make the thing jump like a jackrabbit. Unless there is something odd about this decoder where another setting you have is overriding or making it ignore CV2. Try doing a reset (CV30=2) and starting clean.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
What is the value of CV29? Make sure you don't have it set to use speed tables, because if you do it will not use CV2.
The reset cured the problem, initally it did reverse the direction. I'm guessing this was an open box item at Caboose Hobbies and it was one of 5 remaining DCC locos that they had, maybe it was not as new as I expected.
CV29 is 33, the problem has been solved by a reset using CV30