I have a 46-inch flat screen a few years old, a while back I had problems and called Rogers; went though the tests and they recommended a new HDMI cable, well it solved the problem. The prices range is ridiculous, they recommended a cheap one would work and it worked fine until last night, probably a year or so. Thought it was the TV gone. The last time I bought a new HDMI and after found two new ones that came with other electronics.
I pulled one out plugged it in and problems are solved. SO if it happens to you give a new cable a try. A lot may have chucked the TV, I had those thoughts. Worth a try for the price of a cable . . .