I bought an older 50inch Vizio on craigslist and it was working fine for about 2 months, then one day I was watching it and all the sudden the picture went out and the menu buttons lit up but wouldn't work. It turned out that a surface mount fuse between the psu and main board blew, it was the one for the 5v rail.
Not having any smt fuses around I just removed it from the board and boged in a glass fuse which I soldered wires to the end of and heat shrinked.
When I turned the tv back on the picture looked weird like someone added sharpening noise in photoshop. I noticed it was only bad in 1080, so I just watched it for a day in 720p. The next morning it wouldn't even switch to 1080 and after an hour the noise was really bad in 720 also.
All the caps look fine but the way the problem slowly got worse I'm wondering if caps could be the issue? Or maybe the wires and glass fuse is acting like an antenna or something causing noise? Or does this sound like the chip that handles hdmi is dying? The issue is the same on all hdmi ports no matter what input device is plugged in to them.