My bet is that a tech will have to diagnose it next.
Can you reveal if any on screen menu shows up?
My Samsung 2011 Plasma TV Model #PN51D440A5DXZA has no picture but does have sound. It was working fine prior to installing the Chromecast device.
I installed Chromecast on the HDMI 2 input and used the USB port on the side of the TV. Chromecast was working fine then shortly after, the TV screen went black and video never came back on the TV. I removed the Chromecast device and reset the TV to factory settings but no video. I tried using the other inputs on the TV but still have the same issue - no video but do have audio.
I worked this through the Chromecast forum but no luck in getting the TV video back in operation.
I also opened a support case with Samsung but they referred me to a local service center so I wanted to check with this forum to see if any of you had some ideas or could let me know which order of the internal TV circuit boards I could start to replace.
Many Thanks, David.