Facing TV Problems? Ask a TV Technician.
Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I advise you to get a service manual for this model or for this model line. It may save you ever so much expense swapping boards out until you find what the problem is - if you ever do by that method.
(My personal opinion - it's just an opinion, without better and more in-depth data - is that you have a shorted component somewhere in the TV.)
Here's one source for such a service manual:
And this is another source - a proved, reliable source that I have often recommended to customers without ever hearing back anything bad - and it's also about 6-7 $ cheaper:
I hope this advice helps with the problem.