How can I resolve the following problem I switch on the TV and every time I have to go through the start up menu which I exit then answer Yes then I press AV and HDMI the blue screen comes ends saying NO signal I then turn on my Sky and the programmes list come up please help. We have tried setting the tv up but it doesn't deliver any programmes. My TV was purchased just under 2 years ago but I can't find the receipt. I paid cash for it.