What frequencies do ITV1 and Channel 4 broadcast on?
to retune, you just rescan. Manual tuning just forces it to rescan one channel. if the signal is not strong enough, then it wont change what it can detect in the Multiplex channel. It seems that the new TV is less sensitive or has a higher error threshold before it is willing to show the picture. As the change is so marginal, it will in all probability be solved with a simple Aerial amplifier – but make sure it has some 12-15dB or more factor, not a simple room spliting one. Maplin and Argos do some. if that does not solve it (and you can take it back to argos if you look after it enough to look new), you will need a new Aerial (and they do get old/tired) and/or Masthead amplifier to boost the signal before it gets lost down the cable in the noise.
