Does the red light by the power button give you a code by flashing a certain number of times? It sounds like you'll need a replacement board. Models like yours usually don't have individual led driver or backlight inverter boards. Those are probably part of the power supply board. You can take the tv apart and remove the screen to access the led strips. You can test each light with a multimeter and should read 3 volts at each one. Sometimes the connections on those strips are bad and you can fix them with a soldering iron. It's a bad connection/component on one of those. You can inspect the capacitors of the power supply/led board for visable damage just by opening up the back and using a flashlight. They're will be larger caps grouped closer together on half the board which is the power supply side. So you'll want to look at the smaller spread out ones on the opposite side. They're usually 10-35v ones usually blue, black or brown tubes with an x on the tops. Look at that x and check if it's puffed up. They should all be flat. You will be able to tell if you've found a puffed one compared to the rest. If you do find a bad cap it is 99% that board. Or you could just replace the caps. If not I'd check the led strips for bad connections. Hope that helps
It could be either or both. If you have backlight for 5-10 minutes it tells me that it manages to drive the LEDs however, something in the circuit cannot sustain the power delivery. I'm guessing capacitors that are drying out on the backlight circuit.