Most likely the power board inside is bad. If you are brave enough and handy with electronics you can take it apart and look at the capacitors on the powerboard, those are the usual starting points as they are the most likely thing to fail. If that's the problem it will cost you less than $20 to fix it yourself... I am assuming that you get no sound or anything else... if you get sound and no picture then it could be the bulbs behind the LCD which would be different fix and might be very difficult because it is hard to find the right bulbs for some LCD TVs... but the capacitors on power boards are easily found for any TV.
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Most likely the power board inside is bad. If you are brave enough and handy with electronics you can take it apart and look at the capacitors on the powerboard, those are the usual starting points as they are the most likely thing to fail.
If that's the problem it will cost you less than $20 to fix it yourself...
I am assuming that you get no sound or anything else... if you get sound and no picture then it could be the bulbs behind the LCD which would be different fix and might be very difficult because it is hard to find the right bulbs for some LCD TVs... but the capacitors on power boards are easily found for any TV.