If you cannot receive on one TV,  follow this procedure:

1) Make sure the Modulator is set as per the manual ( Reset to default )

2) Connect a TV Direct to the Modulator with a short piece of cable


3) Turn on the modulator and scan / find the modulator channel on the directly-connected TV on your test bench

4) Inject the modulator to your distribution, and use the same TV as a " TESTER " to check if the signal is received at the endpoints.

Since this TV was working directly connected to the modulator, it must work the same when you use it on the other side of the distribution cables

If it does not receive, you can determine if it is a bad cable, a bad splitter, a bad amplifier, or a frequency jam so you need to change the channel on your modulator.

Use this TV to troubleshoot what is blocking the signal