SOUND NO PICTURE ONLY RAINBOW
I just fixed this problem on my neighbor TV. I don't have a manual or schematic, and didn't pay any attention to the reference designators, so I will just have to describe it. The problem was a bad solder joint. Visible thermal fatigue. Looking at the main board, (didn't even need to slide the cassis out). There is a small, narrow, vertical board in the center, adjacent to the yoke connectors with a funny looking little transformer on the very top. Check the connections on that.