You do not need separate pre-amps. Such a circuit is very, very rarely needed.
Verify that your wiring circuit looks like this one:
https://www.antennasdirect.com/cmss_...e_Antennas.pdf
Verify that you did not leave any splitters or any other device in the line between the preamp and its power inserter if you are repurposing existing cable. Doing so usually starves the amplifier of its power turning it into a brick wall for signals.
If necessary, break the system down, ones step at a time, to the last known basic working configuration, for example, C5-amp-inserter-TV or alternately, the DB4e-amp-inserter-TV. Verify each subsystem works correctly before integrating them into the complete system.