Samsung ps50c450b1w sound but no picture. Tested Vs and Va voltage and both hit correct voltages then quickly drop to zero after initial start up. Bottom ic on y buffer is blown. Still have same results with y sustain and y buffer detached from power supply board. I suspect Main board as the correct voltages are seen at the first connector.
Heatsink on main/video board gets hot and logic board LED is blinking on and off in a steady pattern.