We've been seeing many 2014 E550i-B2, E550i-B2E Vizio TVs with intermittent symptoms. The set will play work a while and then the picture will go out with the sound working. Or Both picture and sound will go away. Turning it off and on may get it to work again for a while.
This is a same day repair in most cases.
You can try the light test on this problem. Shine a bright light into the screen and you may be able to see the picture is there. The problem is the LEDs behind the screen are not turning on.