How can I fix my Goodmans tv model GTV26WLCD?

I have 2 scart leads in the back one for my video sender (sky) the other for my video/dvd player. Sky is in scart 1 dvd in 2, the sky works fine however I cannot receive the dvd picture sound is fine just no picture? I have changed the scart leads around and still the same. I have used the scart and dvd player in other tvs and no problems, just when I connect it too the Goodmans tv? I cant get into the tunning screen on the tv? please help.