I have the same problem and decided to replace the whole power board; filter board and TNPA4774AG SS Board... still not working.. then using my oscilloscope i measured the frequency, and noticed that it was the RF board, N7AE or 1AA4B1ON22900.. All these parts are available from Shop Jimmy.com I compared prices with a TV repair shop and there was a massive saving if you do it yourself. ( If you know how to unplug a power socket, then you can do this yourself ) TV SERVICE GUY $695 plus labor Shop Jimmy.com $250, FREE SHIPPING.