I have the same iss with my series 7 smart tv.
I had sky and have a good signal on both sky cables. I connect either cable to the tv to get free sat and throw sky out. It depends were I check sometime I have a good signal but checking a different way I have zero signal. Trying to set up freesat it says I have a 76% signal strength and a search for channels says my postcode is incorrect it then searches and finds and store nearly 200 channels - select 101 gives BBC London but there is no picture and it wants me to scan again.
how can I get my freesat channels back. They were all working before the skybox was connected. The sky engineer did change my LNB when he installed the box is this something to do with the problems with signal but why is my postcode which was saved in the tv from last time being rejected at invalid. My software version is 1242 which it says is the latest.
I need to get freesat working again as the sky box needs to be returned.