Question : KDL55HX701 or  55LH90, which is best/newer?

I purchased an LG LCD (55LH90) for $1500 at a local store (Costco).  I bought it a bit cheap because I purchased the last model they had.  I have the TV connected through a coaxil connection for cable.  I presently do not have DirectTV or Dish network so I don't have access to a box, which also bring out another question...Is there a device I can get that's HD that my coaxil can connect so I can receive HD programming?  Also, back to my original question, which TV is best?  I'm planning on getting FTA (for those who know what this is) to watch PPV boxing and MMA and movies as well, and of course, regular cable TV.  I just want something that has a crisp image and while watching TV, I don't get that feeling.  But when I put in a DVD, the image is amazing.  

I'm confused...Should I shell out another $300 for the  KDL55HX701?  Is it worth it, eventhough I'm be getting one that is not OPEN?

Answer : KDL55HX701 or  55LH90, which is best/newer?

Which, again, means that the motherboard is shorting out between itself and the battery. This is a power issue most likely fixed by replacing the system board.