Supersonic TV does not turn on...?

I have a Supersonic SC-222A-BK digital flat-screen TV that is AC/DC capable. The power indicator light does not turn on, nor the TV itself. This occurs when the original AC power converter is used. I was wiring a dedicated 12 volt source to it from a new fuse box I had recently installed and I think I reversed the 12volt polarity to the TV. Is it worth it to repair it, or have I possibly ruined it?