If your tv shuts off and on, then is normal for a couple seconds then goes to colourful lines and patterns the fix is easy.
Take the back panel off your tv, find the ribbon cable that goes from powerboard to motherboard.
It's ribbon #20. You'll note on the power side there's likely discoloration around some of the pins.
The best way to repear it is by soldering two wires from backside of connector on Powerboard and to the cable #20.
It's just the two end ones and it is easy to do.
This is what the screen can look like with error.
Motherboard is on the left and powerboard is on the right.
Here you se the burned connector on the powerboard.
Like a heart bypass I have made a plug bypass and this will last a lifetime.