Hi, it sounds like the problem is internal to the Tv, but yes its likely the input connector board that has failed. This happens quite a bit. And it is usually the problem with this set.
It will require soldering to replace that so you have to be experienced at that or your likley to cause further damage to the set.
I would take this one to Best Buy or Sears for this service. They are fair priced and do quality work;-)
I wish I had better news for you on this I really do.
In any case, I will stick with you until this is complete.
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