Diesel engines require air, fuel, and compression.
I agree with jacwjames, that fuel delivery is the most likely problem. Change out filters, cycle the ignition several time to ensure not only that the new filters are full, but that fuel has reached the main fuel pump. Then, try again.
The "fly in this ointment" is if you have any dash lights that are not cycling ON during the initial turn of the ignition, or any other electronic indicators that are failing.
Post your results.
Larry, Eileen, and Finley
2004 Alpine 36FDDS
Third motor home, first Alpine, no need for another.