Two Methods Of Switching Power Supply Maintenance

1. Short-circuit method

Most of the 120w smps of the LCD display adopts a direct sampling voltage-stabilizing control circuit with a photoelectric coupler. When the output voltage is high, the short-circuit method can be used to distinguish the scope of the fault.

2. Series bulb method

The series bulb method refers to removing the fuse of the 12v 10amp smps input circuit and stringing a 60W/220V bulb at both ends of the fuse. After the AC voltage is passed, if the bulb is very bright, it means that there is a short circuit in the circuit. The bulb has a certain degree of resistance, such as a 60W/220V bulb, whose resistance is about 800n (referring to thermal resistance), and the bulb plays a certain current limiting role. First, the brightness of the bulb can be intuitively judged to be roughly the fault of the smps 10a 12v circuit through the brightness of the bulb, and second, the current limiting function of the bulb will not immediately burn out the components of the short-circuited circuit. After the short-circuit fault is eliminated, the brightness of the bulb will dim, and then the bulb will be removed and the fuse will be installed.