Well I googled it and there are many mentions of power supply problems.
Thoroughly inspect the power supply for bulging capacitors etc.
Without looking at it myself this is about all the info I can give you.
If it does have bulging capacitors or some other problem with the PSU it might be on its own board that you may be able to purchase a replacement power board. But if the price of the board is half as much as the TV you might as well buy a new TV.
2600k@4848mhz @1.4v CM Nepton40XL 16gb Ram 2x EVGA GTX770 4gb Classified cards in SLI@1280mhz Stock boost on a GAP67-UD4-B3, SBlaster Z powered by TX-850 PSU pushing a 34" LG 21/9 3440-1440 IPS panel. Pieced together 2.1 sound system