Why did half my screen go dark?

Why did half my screen go dark?

why did half of my sanyo tv screen go dark? right half of screen went dark like a shadow over it. I can still see picture and everything else works.

ANSWERS:

Hi. The leds are controlled by a separate driver board on this Sanyo model. The board controls the voltage to the leds and is supplied by the power board. Very often its not the backlights themselves but the driver board on this model. Replace with same part and should be good to go. Of course the right way to check is with a led power supply or tester. Check each channel on the leds. There two sets on the left side of driver board bottom and one set on the right side. The first 2 sets should run about 70 volts each while the one on the right should run about 140 volts.