No signal from isolator??

[piojoa]

Hi there,
In my house i have 3 white ntl boxes on the inside of my walls in 3 different rooms. I believe these are called isolators? (they have 2 F connection outlets FM/TV)
Anyway i`m trying to move my set top box from one room to another and when i connect the set top box the the new unused isolator box i get no signal LD20 fault. Does the isolator need activating & can i do this? ;)
Many thanks for any advise

[MovedGoalPosts]

:welcome: to Cable Forum :tu:

Although the white boxes, which are simply connection points, exist, they may not be wired back to the cable network. You might need to do some tracing of wires to see what is what. It's possible they were connected but were disconnected at the master splitter if there was an interference issue, especially if they wern't needed at the time. Where they installed by or for you, or are they there from a previous owner who could have done some fiddling. In some cases they might even have been linked to a satellite dish rather than cable?