中文
含义
LED指示灯闪烁12次，表示待机电源故障。该代码表示电源板的待机供电电路（Standby Power/5VSB）异常，这是电视在待机状态下维持遥控接收和系统唤醒功能的关键电源轨。待机电源故障会导致电视无法开机、遥控器无响应或间歇性自动开机。
常见原因
- 待机电源IC（如TNY系列/Power Integrations芯片）损坏，无5VSB输出
- 5VSB输出滤波电容老化漏液，电压纹波过大
- 待机电源变压器绕组短路或开路
- 光耦反馈电路（Optocoupler）老化导致电压反馈失调
- 主板上待机电路存在轻微短路，拉低5VSB电压
自助排查
- 测量电源板待机输出端（通常标识为STB或5VSB引脚）电压是否在4.75V-5.25V之间
- 断开电源板到主板的连接器，单独测量空载时5VSB电压是否恢复正常
- 如空载正常而接入主板后电压被拉低，表明主板待机电路有短路
- 如空载即无5VSB输出，需更换电源板或维修待机电源电路
English
Meaning
The LED indicator blinks twelve times, indicating a standby power failure. This code indicates an anomaly in the PSU’s standby power circuit (Standby Power/5VSB rail), the critical power rail that maintains remote control reception and system wake-up capability when the TV is in standby. A standby power fault will prevent the TV from powering on, render the remote unresponsive, or cause intermittent automatic power-on.
Common Causes
- Standby power IC (e.g. TNY series / Power Integrations chip) damaged, no 5VSB output
- 5VSB output filter capacitor aged or leaking, causing excessive voltage ripple
- Standby power transformer winding shorted or open
- Optocoupler feedback circuit aged, causing voltage feedback drift
- Minor short circuit in the standby circuit on the main board, pulling down the 5VSB rail
Self-Check Steps
- Measure the standby output pin on the PSU (typically labeled STB or 5VSB) — voltage should be between 4.75V-5.25V
- Disconnect the PSU-to-main-board connector and measure the 5VSB voltage under no-load to see if it recovers
- If 5VSB is normal under no-load but drops when connected to the main board, the main board standby circuit has a short
- If there is no 5VSB output even under no-load, replace the PSU or have the standby power circuit repaired