I have an emerson hdtv that wont turn on how can i begin to trouble shoot this problem?

1- Make sure the outlet you are plugged into HAS power with a lamp, etc. and not on a wall switch. Larger sets have power cords like computers and come loose- be sure it is seated firmly. Do ANY power lights come on? If not, an internal fuse may have blown. If there was lightning or power company outages and surges these can fry your set if not protected with a UPS or surge suppressor, which do not provide 100% coverage under all conditions.