Aerial amplifier problem

[BraveSirRobin]

My dad has just moved into a new house. The previous owners have left a Triax F100/1 unit plugged into one of the aerial points. This is obviously powering a masthead amplifier - TVs elsewhere in the house don't get a signal unless it's powered on.
We've connected the "TV" cable of the F100/1 to another TV, but it's just showing "no signal". The TV has a digital tuner, so why doesn't it find any channels? I'm told the previous owners had a TV working in the same location.
Must be missing something obvious, but what?

[megaphone]

That's a strange one. Could be too much signal/gain. How many other TV points are there? There's likely a TV distribution amp or splitter somewhere, in the loft?

[bristolracer]

May sound obvious but have you done a retune on the affected TV
You may have moved transmitter areas when you moved?
Try a full scan replace existing channels or factory reset option, this wipes the TVs memory and forces it to go and find the signals again.
Otherwise my guess would be a cable fault from the power supply (the TV out to the Tv itself bit)