I recently replaced the main board because of no picture/sound and TV would not turn off unless unplugged. Main board (from Vizparts) replaced, everything seems to work except HDMI and optical audio. No signal on HDMI 1,2,3 and 4. Composite (R,W,Y) and component (G,B,R) connections work. That's when I tried the optical audio from the DirecTv receiver, but no audio. Composite audio and video are what I'm using now. Reset to factory settings no help, unplugged for over an hour no help. Anything connected to HDMI, TV displays "No Signal" Is there anything else besides the main board that could be the problem before I call Vizparts?