This is going to be much more complex than you might think. The tv has an internal failure that will require diagnosis with a meter, ordering parts, installing the parts (likely involving soldering). If that is something you want to attempt then reply back here and I can assist you further (a meter and soldering experience is required).
If you are unable or unwilling to perform any of these procedures then a repair shop should be consulted. But I can tell you our shop charges $125 to come diagnose the problem and hand you an estimate. Then another $200 in parts and labor (if it's just a board). So the total can be $325 (or more). To find a trusted local repair shop near you, enter your zip code at www.tvrepairpros.com
Remember that I am here to help you. Please reply back if you need clarification on any of the above.
Regardless of what you decide to do next, please be sure to click the 5 STARS rating at the top of the page. Keep in mind that I have donated my invaluable time and expertise helping you rather than other paying customers.
Rating now does NOT close the question or prevent us from continuing our conversation here. My livelihood truly does depend on your positive rating.
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