I have insignia ns-27lcdi am having problem with my tv when i turn it on it turns on the red sign of power turns blue but screen stays black and no picture or sound and i can't do anything?

It sounds like your set is looking for an input device. If you have cable/satellite, be sure (from the menu) that you have it set for cable(same as satellite) or AIR, if you're using an antenna. The blue light sounds like the input source is set for video(dvd), games, or Video tape.