Chris

Right ... So, "something" has caused something else to get broken, during the course of all the unplugging and installing you have been doing.

I'm not sure what you mean by "there was an amplifier before". Where was it, what was it connected to, and why isn't it there now?

We need to break this problem down into its component parts in order to discover where the problem is. You have an aerial on your roof, with a single cable coming down from it. At some point, that cable is split, almost certainly via a powered amplifier, which allows the signal to then be run by multiple cables to the other rooms in your house.

So, where is that amplifier? Is it the one that you had "before" or do you know there to be one in the loft? You need to check and ensure that you still have a working amplifier at the point where the single aerial from your roof is split off for the various rooms in your house.