Due to the large number of LED power supply, the driving mode is also varied, this article will give an example of a LED switching power supply isolation drive

1, check the driver board, if there is obvious signs of burnout, should first consider replacing the original device, such as the fuse circuit and rectifier bridge in the preceding stage, these two components are easily damaged by surge voltage and current components.

2, if the output voltage is unstable, there may be feedback loop and switching circuit problems, check the switch driver IC, optocoupler and regulator IC is caused by the power, if the damage will be considered to replace.

3, if the drive board burned too bad, will consider replacing the driver board, PCB board line damage will not be necessary for maintenance.

4, measuring the constant current module input power: 100VDC, 12VDC is normal; if the input voltage is too low or no voltage, then AC / DC power supply has been protected or damaged;

5. If the fault persists through the above steps, check the EN signal section, connect the pin 5 of the constant current IC to the pin 3 of the constant current IC with a wire, and then turn on the power test. If the LED light bar can be lit normally, check the EN signal The EN signal provided by the AC / DC power section is normal.