Sony KV-ES34M9S TV, internal breakdown of the line output transformer.
For the Sony KV-ES34M9S TV, during the process of turning on and watching a program, the raster suddenly disappeared, but the power indicator light remained on.
Analysis and Maintenance: Initially suspected damage or protection in the horizontal circuit. One end of the +B voltage output circuit R6849 and R6850 was desoldered, and a 150Ω/1W resistor was temporarily connected on the back of the printed circuit board. Through this resistor, the horizontal current was reduced to prevent the overcurrent protection from triggering. At this time, when the machine was turned on, the voltage drop across this resistor was checked, and it was calculated that the horizontal current was around 500mA, indicating an internal breakdown short-circuit phenomenon in the line output transformer T6803. Touching the shell of T6803 revealed a noticeable temperature rise. After disconnecting the current-limiting resistor, it was found that T6803 had serious heating issues, leading to the conclusion that there was a local breakdown short-circuit in T6803.
Solution: After replacing T6803 with the same model, the fault was eliminated.
Source: Beijing Sony TV Repair Center http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3682079.