I have the exact TV with the same exact problem: Red power LED lights up but no image. Press on led power button, it blinks then it comes back but no image. I can see the HISENSE dimly lit if I use a flashlight.
I bought the LED strips from www.shopjimmy.com and I tried the the fix as shown here and IT WORKED!
https://youtu.be/rcZh_HflXQc
It looks a lot worse than what it is. I did buy the suction cups from shopjimmy.com as well (even though the guy in the video didn't like them) because it was convenient. I was just really careful with that.
It would be a good idea to have someone help when removing the screen. Otherwise, this is a one-man job. I don't have any experience doing this but I do like to tinker with stuff, and I was able to do this in about 2 hours.
Hope it helps!