When this TV set came to my shop there was a white line across the screen. When hitting the side of the TV set, the picture comes back for a while then the horizontal line show up on the screen again. With this problem showing, I headed directly to the vertical section starting with the IC AN5515 and started checking for loose or cold soldering joints. As I scanned the area with a magnifying lens, I could not see any loose or cold joints. I turned the TV on and started checking for the voltages on the IC. There were no voltages reaching this IC. I traced the VCC line back to the fly back transformer because I know that is where the 24 volts come from.
As I was tracing the ACD line with a magnifying lens, I came across a resistor that is acting like a fuse and one of its legs was loose. I soldered that resistor out of the PC board and I checked the integrity of it and found it in bad shape. It was 4.2 ohms located in (R555) in the high volt area.
I put another one in and soldered the two legs. The moment I fired up the TV, it worked fine for a while then the horizontal line was displayed on the screen again. I checked the resister that I put in and it was fine. I traced it back to the vertical IC AN5515 and checked the voltages there and there was 24 volts reaching that IC.
I checked all the capacitors in the vertical section with ESR meter and they all checked fine. It seems like this IC was getting weaker in this set. So I decided to put a new one in and fired up the set. It worked nicely for a long time.