It is a very common phenomenon that LED lights become darker as they are used. To summarize the reasons why LED lights can be dimmed, there are no more than the following three points.
Drive damage
LED lamp beads are required to operate at a low DC voltage (below 20V), but our usual mains supply is AC high voltage (220V). To convert the mains power into the electricity needed for a lamp bead, a device called an LED constant current drive power supply is needed.
Theoretically, as long as the parameters of the driver match the lamp bead plate, it can be continuously powered and used normally. The internal structure of the driver is relatively complex, and the failure of any device (such as a capacitor, rectifier, etc.) may cause a change in the output voltage, leading to dimming of the lamp.
Driver damage is the most common fault in LED lamps, and can usually be resolved after replacing the driver.
LED burned out
The LED itself is composed of a combination of lamp beads, and if one or some of them does not light up, it will inevitably make the entire lamp dim. The lamp beads are usually connected in series and then connected in parallel - so if a certain lamp bead burns out, it may lead to a batch of lamp beads not lighting up.
After burning, there are obvious black spots on the surface of the lamp beads. Find it, connect it to the back with a wire, and short-circuit it; Or replace it with a new lamp bead, which can solve the problem.
Occasionally, one LED burns down, which may be due to coincidence. If you frequently burn out, consider the driver issue - another manifestation of a driver failure is burning out the lamp beads.
LED light attenuation
The so-called light decay is that the brightness of the light emitting body is getting lower and lower - this situation is more evident in incandescent and fluorescent lamps.
LED lamps cannot avoid light decay, but their light decay speed is relatively slow, and it is generally difficult to see changes with the naked eye. However, it is not ruled out that objective factors such as poor quality LEDs, or poor light bead plates, or poor heat dissipation, may cause LED light to decay faster.