Hello, My name is ***** ***** I'll be assisting you. I'm sorry you're having problems.
The first thing you would try, is disconnect the set from power, then press and hold the power button on the TV itself (not the remote), for 10 seconds and release. Then plug the set back in, and also check that the power cord is connected tight at the TV as well. Press power once, and see if the set powers up normally.
If the issue persists, then unfortunately this does indicate a hardware fault in the set. Either with the power board or Mainboard that requires repairs. There aren't any quick fixes for this aside from trying to leave the set unplugged for several hours in the hopes that it resets. The average cost for this repair is in the $250-$300 range (depending on which board has failed) and if you'd like you can use the link below to locate a shop in your area:
Alternatively, if you're a DIY type and looking to repair the set yourself, then reply back here and I will have a few checks for you to perform.
Other than that, I'm sorry for the bad news here and wish there were a quick fix.
If you need further assistance let me know. Before you go, PLEASE DO click at least a 3 STAR RATING, at the top your screen. That is how I am credited for my efforts by the site.