Reasons for LED blinking:

1. Large output voltage ripple, parallel capacitors at both ends of the LED.

2. Components on the PCB board change with temperature, such as NTC negative temperature coefficient thermistor on IC pins; this can be corrected to normal resistors.

3. The startup voltage of the IC on the PCB board is too low, or the auxiliary winding terminal voltage is in the on/off state, causing power supply "hiccups" and LED flashing.

 4. Since the LED is a current device, its forward voltage Vf decreases by 2mV for every 1 degree Celsius increase in temperature. When the LED heats up during operation, its Vf value will decrease according to the above relationship, which may also cause feedback control terminal VCC to drop due to the drop in the output voltage of the power supply. If the voltage drop at the VCC pin exceeds the cutoff voltage of the IC, it may cause the circuit to enter the restart mode, leading to LED flashing. Therefore, a linear voltage regulator must be added to the VCC pin.

5. The output voltage is too low to start the load, or the output voltage is higher than the maximum voltage of the load.

6. The protection resistor of the power supply is damaged, such that the resistance value increases to 2-3MΩ, resulting in insufficient AC input voltage and causing the power supply to be in a restart or undervoltage state, resulting in unstable output voltage and flashing.

7. The LED light flashes a few times (about 3 times) after power failure because there is excess charge on the inductive or capacitive component at the output end. Adding a resistor of several tens of K~100K in parallel with the output end and capacitor can solve this problem.

8. All LED lights blink during the aging process.

Reason: The power of the control box that controls the aging frame switch is too low. For example, for 270 18W LED fluorescent tubes, the total output power is 24 strings of LED30.24A270/0.9=5184W, and the total output current is 0.24270=64.8A. Therefore, if only a 60A control box is used, due to the overload of the control box, the timing switch on the control box will malfunction, causing all LED lights on the aging frame to blink.