It sounds like a board, cable, connection or panel failing. Get estimates.
Every now and then our 55LM7600 will blur parts of the bottom 1/3 of the screen. It's a quick snap out of focus for a few seconds and then back into focus. It's most noticeable with subtitles or shows that have their logo in the bottom. It doesn't seem to effect the top or center of the screen and it's intermittent. Some nights we can watch TV all night and not see it, others we see it snap in and out of focus every 30 seconds or so.