Blue screen on tv?

I have a mikomi dvd/tv and have never used it as a tv before. The children connected the computer to it and only used it for that. We boxed it up for the past year since they got a wii and now when I turn it on I only get a blue screen. I cant seem to do anything with it. The dvd player make all the sounds and opens and closes but I cant change channel or get off the blue screen displayed. Please help