I have a brand new Hitachi(6 months) hitachi 42 inch TV and am having problems running a new ps3 system throug the hdmi cable link .nothing works any ideas?

When you say "nothing works" do you mean that you have already tried some solutions with no results? If so, please tell us what you've already tried.

What is the model of the TV? Does it work when connected through the supplied cables with the PS3? If so, check the resolution settings. You could have it set to 1080p, when the TV is only 720p or 1080i.