**English Translation:**
Haier TV has a red indicator light on, but there is no sound or picture. Repair techniques. Source of information: Beijing Haier TV Repair Center http://blog.163.com/hisense_dianshi/.
**Analysis and Inspection:** After powering on the TV, use a multimeter to measure the rectified output voltage of +300V from the power supply, which is normal. The main switch-mode power supply briefly outputs voltage when turned on, but it quickly drops to 0V, indicating that the switch-mode power supply itself can oscillate. Measure the control transistor Q554's b-terminal voltage in the protection circuit, which reads 0.7V, meaning Q554 has been conducting, indicating that the protection circuit has been triggered.
By disconnecting each control point in the protection circuit one by one, when disconnected at the c-terminal of the overload protection circuit control transistor Q806 for the +140V line, a voltage output appears at the +140V end, but it is very low and accompanied by a strong "squealing" sound, indicating an overcurrent fault in the +140V power supply.
After turning off the power and measuring the resistance between the +140V load terminal and ground, the forward resistance value is measured as 22kΩ, with no obvious DC short circuit, suggesting an AC overload. By short-circuiting the secondary side of the horizontal drive transformer T551 with a wire, after turning on the power again, the +140V voltage returns to normal. Checking the horizontal output transistor and flyback capacitor reveals both are normal, thus determining that there is a partial short circuit in the high-voltage winding of the horizontal output transformer T501.
**Repair Method:** Replace the horizontal output transformer T501, and the unit operates normally.