UN55MU650DFXZA TV. Lost power. Now will not turn on. Fuse? Pwr supply

Ray Ferrell  if your TV shows no sign of life you will need to check the power supply first. The power board for your TV is most likely a BN44-00807A You’ll find one fuse just north of the power cord connector (FP801S). Check with a meter for power to it and check it for continuity. We will have to see your boards to give you more directions on what to check. I’d proceed with the power to the board and then the connector (CNM803) from that board to the main board. The voltages will be printed on the power board itself. Also check the standby voltage on DM845C at DM853C from “center leg to center leg” it should be 8V. For now it sounds like a power board issue but can also be the main board since that is the board which tells the power board to turn on. Adding images to an existing question