It is a very common phenomenon that LED lights become dimmer with use. To sum up the reasons that can make LED lights dim, there are nothing more than the following three points.
The drive is damaged
LED lamp beads are required to work at DC low voltage (below 20V), but our usual mains power is AC high voltage (AC 220V). To convert the mains power into the electricity required for lamp beads, a device is needed called an "LED constant current drive power supply".
Theoretically, as long as the parameters of the driver match the lamp bead board, it can continue to be powered and used normally. The inside of the driver is relatively complex. Failure of any device (such as capacitor, rectifier, etc.) may cause the output voltage to change, which in turn causes the lamp to dim.
Driver damage is the most common fault in LED lamps, and it can usually be solved by replacing the driver.
LED burned out
LED itself is composed of lamp beads one by one. If one or part of them does not light up, it will inevitably make the entire lamp dim. Lamp beads are usually connected in series first and then in parallel - so if a certain lamp bead burns out, a batch of lamp beads may not light up.
There are obvious black spots on the surface of the burnt lamp bead. Find it, connect a wire to the back of it, short-circuit it, or replace it with a new lamp bead, which can solve the problem.
Occasionally one LED burns out, maybe by chance. If it burns out frequently, you need to consider the driver problem - another manifestation of driver failure is burned out lamp beads.
LED light attenuation
The so-called light attenuation means that the brightness of the luminous body is getting lower and lower - this situation is more obvious in incandescent lamps and fluorescent lamps.
LED lights 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 does not rule out that inferior LEDs, inferior optical bead boards, or objective factors such as poor heat dissipation may lead to faster light decay of LEDs.
