**Konka After-sales Case: T2916N TV Powers On with No Display, No Image, No Sound, but Power Indicator Light is On**
**Fault Symptoms:** A Konka T2916N TV powers on with no raster, no image, and no sound, but the power indicator light is on.
**Analysis and Maintenance:** Upon inspection, it was found that there was no voltage output from the +B line, and a buzzing sound could be heard. This noise was determined to be caused by a short circuit between the +B line (horizontal power supply) and ground. Testing revealed that the collector of the horizontal output transistor V402 was short-circuited to ground. After removing V402 for further testing, it was confirmed as damaged. By disconnecting L906 and connecting a 100W/220V bulb as a dummy load, the +B voltage rose to approximately 200V, indicating that the excessively high +B voltage had caused the damage to V402. Further checks showed that the sampling voltage regulator circuits N901 and N902 were functioning normally. However, the base voltage of the high-power power switch transistor V901 increased from 2.6V to 0.3V, revealing that capacitor C906 was faulty.
**Repair Method:** Replacing C906 resolved the issue.
**Source Article:** http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3761213