Chosen Solution
The backlight turns off but TV it’s still on, I can hear sound and change channel. The failure appears between 2 minutes and more than 1 hour. If the LED turns off and I turn the TV off and on again the LED will not turn on, but if I disconnect the power supply and reconnect it the LED comes back and then fails again. I changed the power supply about two months ago because the TV was not turning on at all, and after about 2 weeks it started doing that. At first I thought the issue was the cables feeding the LEDs and I cut them to use a new section as 4 years ago I needed to do a similar repair but after doing this the problem is still present.
Forgot to update this, I fixed it by changing the mainboard.
