Solution to LED light flickering after turning off the light

Infineon / Mitsubishi / Fuji / Semikron / Eupec / IXYS

Solution to LED light flickering after turning off the light

Posted Date: 2024-02-02

LED lamps refer to lamps that use light-emitting diodes as light sources. Generally, silver glue or white glue is used to solidify the semiconductor LED onto the bracket, and then silver or gold wires are used to connect the chip and the circuit board, and the surrounding area is sealed with epoxy resin. , to protect the internal core wires and install the outer shell.

LED lights are gradually dominating the current electric light market due to their high brightness, low energy consumption, and long life. Generally speaking, it is difficult to have problems with LED lights. Among the problems with LED lights, there are no more than three problems: the light does not light up, the light becomes dim, and it flickers after turning off the light. Today we will analyze and solve each problem one by one.

LED lights come in two forms, one is a ceiling light and the other is a light bulb. Regardless of the type of lamp, the internal structure is the same, which is divided into lamp beads and drivers.

lamp beads

Open the casing of the ceiling lamp or the white plastic part of the bulb, and you can see a circuit board covered with yellow rectangles inside. The yellow on this circuit board is the lamp bead. Lamp beads are the luminous body of the LED lamp, and their number determines the brightness of the LED lamp.


The driver of the LED bulb is installed at the bottom and cannot be seen from the outside. The driver of the ceiling lamp is a black box. When installing the lamp, you need to install the driver first.

The driver has functions such as constant current, voltage reduction, rectification, and filtering.

Solution to LED light not lighting up

When the light does not light up, you should first make sure that there is no problem with the circuit. If the lamp is newly installed, you should use an electric pen to measure it, or install an incandescent lamp to see if there is voltage in the circuit. After confirming that there is no problem with the circuit, you can start the following maintenance.

drive problems

If the light doesn't light up, it's most likely a problem with the driver. Light-emitting diodes have high requirements for current and voltage. If the current or voltage is too large or too small, they cannot light up normally. Therefore, constant current drivers, rectifiers, voltage regulators and other devices in the driver are required to maintain use.

If the lamp bead does not light up at all after turning on the light, you should first consider the problem with the driver. At this point a new drive can be purchased for replacement.

Solutions to dimming of LED lights

This problem should be solved together with the previous problem. This may be the case if the light intensity dims or does not light up.

Lamp bead problem

The lamp beads of LED lamps are divided into strings. The lamp beads in each string are connected in series, and the strings are connected in parallel.

Therefore, if one lamp bead in this string is burned out, all the lamp beads in this string will not light up. If one lamp bead in each string is burned out, the entire lamp will not light up. If one lamp bead burns out in each string, there is a problem with the capacitor or resistor on the driver.

The burnt lamp bead can be seen from the appearance of the normal lamp bead. The burnt lamp bead has a black dot in the middle, and this dot cannot be wiped off.

Inside the red circle are burnt lamp beads

If the number of burnt lamp beads is not large, you can use a soldering iron to solder the two soldering pins behind the burnt lamp beads together. If too many lamp beads are burned out, it is recommended to buy a lamp bead board and replace it to avoid affecting the lighting brightness.

Solution to LED light flickering after turning off the light

If the light flickers after turning off, you must first confirm the wiring problem. The possible problem is the neutral line of the switch control. At this time, corrections must be made in time to avoid danger. The correct approach is to switch the live wire and connect the neutral wire to the light.

If there is no problem with the circuit, it is possible that the LED light generates self-induction current. The simple method is to buy a 220V relay and connect the coil and the light in series to solve the problem.

#Solution #LED #light #flickering #turning #light