My UN55D6000 TV has sound but a black screen with images that can be barely seen. Would this be a problem with the Power Supply board or the Inverter boards (left & right). From a suggestion on a youtube video, I unplugged the connector from the main board to the PS board and the screen was still black. I also unplugged the left inverter and the screen remained black. I then reconnected the left inverter board and unplugged the right inverter and still a black screen. Do you think this is the power board/LED driver? If so, would you know which pins I could measure the voltage that drive the LED's and what that voltage should be? Thanks in advance.