Its the fault in the power supply board . for first unplug the main power cord of the tv for couple of minutes and then reconnect it.also before reconnecting the power cord of the tv again remove all the external device wires connected at its back such as dvd player/vcr etc etc.just connect only tv wire and check out.if still the same problem then its quite possible that the capacitors and ic on the circuit board are getting short in between so the circuit is not getting completed and cutting in between so the tv power led comes but no picture comes up..in this case the circuit board needs to be checked with a multimeter.the faulty and burned out component part should be detected and then should be replaced with the help of soldering iron.to make it proper.to avoid further damage i suggest you that do not on the tv again and again as it will short some more tiny components and the reparing cost will increase as per that.at present its the normal circuit short problem in the tv get it repaired before using the tv again.
also you can get new replaCEment power supply board.this clears the problem completely.
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you can get the required board and components at ----- www.partstore.com -------- or from ------ www.radioshack.com ----
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if you are not familiar with doing this you can get it done by local tv repair technician familiar with this model tv.
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This will help. Thanks please keep updated.please do rate the solution positively .thank you for using fixya.