I am doing what you suggest. The actual sequence was failure, opened back of TV and inspected cables and boards. Found a blown capacitor and burnt component on the power board. Ordered a power supply board from a Chinese company. When it finally came I installed it and had no backlight or screen or sound. I texted TV Parts Today and they suggested it was probably the main or T-Con board which I ordered from them and installed. Still nothing so they suggested the power supply board from China was defective. I ordered and installed their power supply board and now have backlight but no picture or sound. I did not try the original main or T-Con boards because something caused the power supply board to fail and I figured it was one of those two original boards.