中文
含义
背光系统故障。电视开机后有声音但屏幕无显示（黑屏），在强光照射下隐约可见图像，表明背光LED灯条或驱动电路未能正常工作。
常见原因
- 背光LED灯条老化或个别LED芯片烧毁，导致整条灯串不亮
- 背光驱动板（LED Driver Board）输出电压异常或MOS管击穿
- 主板与背光驱动板之间的背光使能（BL_ON）或调光（PWM）信号丢失
- 恒流板上的升压电感或滤波电容失效，造成输出电流不稳
- 电视长期高亮度运行导致LED灯条过热焊点虚焊
自助排查
- 在暗室中用手电筒贴近屏幕，观察是否有极暗的图像内容；若有则确认背光故障而非屏坏
- 检查电源板至背光驱动板的连接排线是否松动或氧化
- 使用万用表测量背光驱动板输出端电压是否在标称范围内（通常60-120V）
- 若以上无法处理，请联系售后更换背光灯条或驱动板组件
English
Meaning
Backlight system failure. The TV has sound but no visible picture (black screen). A faint image may be visible under bright flashlight, indicating the LED backlight strips or their driver circuit have failed.
Common Causes
- LED backlight strip degradation or individual LED chip burnout causing the entire string to go dark
- LED driver board abnormal output voltage or blown MOSFET
- Lost backlight enable (BL_ON) or PWM dimming signal from main board to driver board
- Failed boost inductor or filter capacitor on the constant-current board causing unstable output
- Prolonged high-brightness operation causing solder joint cracks from LED strip overheating
Self-Check Steps
- In a dark room, shine a flashlight close to the screen and look for a very dim image — if present, confirms backlight failure rather than panel failure
- Check the ribbon cable between power supply and LED driver board for looseness or corrosion
- Use a multimeter to measure the driver board output voltage against its rated range (typically 60-120V)
- If above steps do not resolve, contact service for backlight strip or driver board replacement