The failure of the LED lamp is caused by the failure of the power supply and the driver and the failure of the LED device itself. Usually, the damage of the LED power supply and driver comes from the over electric shock (EOS) of the input power supply and the open circuit fault of the load end. The overcurrent effect of the input power supply usually damages the drive chip in the drive circuit and causes the breakdown of passive components (such as capacitors). A short-circuit fault on the load side may cause over-current driving of the drive circuit, and the drive circuit may be damaged due to the short-circuit or overheat due to the short-circuit fault. The failures of the LED device itself mainly include the following situations.
1. Transient overcurrent event
A transient overcurrent event means that the current flowing through the LED exceeds the maximum rated current in the LED technical data sheet. This may be caused by the direct generation of large currents, or indirectly by high voltages, such as transient lightning strikes and switching power supply transients. Overcurrent caused by overvoltage events (such as switching noise and grid fluctuations). These events are short-lived and have a short duration. We usually call them spikes, such as "current spikes" and "voltage spikes." The conditions that cause a transient overcurrent event also include transient overcurrent when the LED power supply is turned on or the power supply is plugged in.
After an electric shock, the failure mode of the LED is not fixed, but it usually damages the welding wire.
2. Electrostatic discharge event
In the manufacture, transportation and application of highly integrated semiconductor devices, electrostatic discharge (ESD) damage is currently the most common transient overvoltage hazard. LED lighting systems must meet the 8kV IEC61000-4-2 standard "human body electrostatic discharge mode" Contact discharge to prevent the system from overcurrent impact failure caused by electrostatic discharge.