中文
含义
电源板故障。电视无法开机、开机后立即断电或间歇性重启，电源板（PSU）未能稳定输出各组直流电压给主板、背光板等负载。
常见原因
- 电源板主滤波电容（大电解电容）鼓包或失容，导致纹波过大
- 待机辅助电源（Standby 5V）芯片损坏或周边电阻开路
- PFC（功率因数校正）电路MOS管或二极管短路
- 电源板次级整流肖特基二极管击穿，造成某路输出短路保护
- 雷击或电网浪涌导致电源板保险管熔断或压敏电阻炸裂
自助排查
- 拔掉电视电源线等待5分钟后重新插入尝试开机，排除电容残余电荷导致的保护
- 检查电源板是否有明显烧焦、鼓包或漏液痕迹
- 使用万用表测量待机5V电压是否正常；若待机5V缺失则为电源板初级故障
- 断开背光负载测试电源板是否单独工作正常，以区分负载短路还是电源板自身故障
English
Meaning
Power supply board failure. The TV cannot power on, shuts down immediately after startup, or restarts intermittently. The power supply unit (PSU) fails to deliver stable DC voltages to the main board, backlight, and other loads.
Common Causes
- Bulging or degraded main filter electrolytic capacitors on the PSU causing excessive ripple
- Damaged standby 5V auxiliary power IC or open resistor in its bias circuit
- Short-circuit in PFC (Power Factor Correction) MOSFET or diode
- Blown secondary-side Schottky rectifier diode causing a short-circuit on one output rail
- Lightning strike or mains surge blowing the PSU fuse or cracking the varistor
Self-Check Steps
- Unplug the TV for 5 minutes, then plug back in and try to power on — clears residual charge that may trigger protection
- Visually inspect the PSU for burn marks, bulging capacitors, or liquid leakage
- Use a multimeter to check standby 5V output; if missing, the primary side of the PSU has failed
- Disconnect the backlight load and test the PSU in isolation to determine whether a load short or PSU fault is the cause