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8 reasons may cause the flexible led strip to be off.


In our use, the flexible led strip sometimes appears to be off, so what are the reasons for the flexible led strip not working? Only by understanding the reasons we can better solve the problem, for this, we summarize eight main reasons why the flexible led strip does not light up:

led strip light
led neon light

#1. Common causes of failure of flexible led strip

1. The packaging protection of the flexible led strip is not perfect, resulting in damage to the leds bead during transportation.

2. The soldering point of the flexible led strip has a phenomenon of virtual soldering, and the vibration during the transportation causes the solder joint to fall off and the flexible led strip to be off.

3. The amount of solder is too small, and the solder joints are easy to fall off.

4. The quality of the solder is not good. The soldering point of the flexible led strip is prone to brittle cracking and falling off during the bending process.

5. The bending angle is too large during installation, causing the flexible led strip solder joint to separate from the copper foil and causing to be off.

6. The product is over-squeezed during installation, causing the leds to be damaged or the solder joints to be deformed and not lit.

7. The soldering layer of the flexible led strip circuit board is too thick, and the solder and the circuit board cannot be completely fused together during soldering, which is also a phenomenon of soldering.

8. The flexible led strip can not be twisted during installation. If it is twisted, the soldering spot of the flexible led strip will fall off and cause no light.

#2. Different flexible led strip in th market.

1. The flexible LED strip is assembled with FPC and assembled with SMD LED so that the thickness of the product is only one coin, which does not occupy space. The general specification is 30cm long, 18 LEDs, 24 LEDs, and 50cm long. 15 LEDs, 24 LEDs, 30 LEDs, etc. There are also 60cm, 80cm, etc., different users have different specifications. And can be cut at will, or can be arbitrarily extended and the illumination is not affected. The FPC material is soft and can be bent, folded, and wound freely, and can be moved and stretched in three dimensions without breaking. It is suitable for use in irregular places and small spaces, and because it can be bent and wound arbitrarily, it is suitable for arbitrarily combining various patterns in advertising decoration.

2. LED rigid bar is assembled with PCB hard boards. LEDs are assembled with SMD LEDs. Or also assembled with DIP LEDs. Different components are used depending on the needs. The advantage of the LED rigid bar is that it is relatively easy to fix, and it is convenient to process and install; the disadvantage is that it cannot be bent at will and is not suitable for irregular places. There are 18 LEDs, 24 LEDs, 30 LEDs,

36 LEDs, 40 LEDs, etc. For the LED strips of hard light strips. There are 18, 24, 36, 48 LEDs with DIP LEDs. Different specifications, there are both front and side, and the sidelight is also called the Great Wall light bar.
led neon light

#3. Here are some ways to identify the quality of LED strips(the flexible led strip quality identification method).

1. Compare the solder joints.

The LED strips produced by the regular LED strip manufacturers are produced by the SMT chip process using solder paste and reflow soldering processes. Therefore, the solder joints on the LED strips are relatively smooth and the soldering amount is not large, and the solder joints extend in an arc shape from the FPC pads to the LED electrodes. The low-quality LED strips to have uneven solder joints, and a dot surrounds the solder fillets. At the same time, different degrees of tin tips appear, which is a typical phenomenon of manual soldering.

2. Compare the quality of FPC.

FPC is divided into copper and rolled copper. The copper foil of the copper plate is convex. If you look closely, you can see it from the connection between the pad and the FPC. The rolled copper is closely integrated with the FPC and can be bent freely without peeling off the pad. If the copper plate is bent too much, the pad will fall off, and if the temperature is too high during maintenance, the pad will fall off.

3. Compare the cleanliness of the surface of the LED strip.

If the LED strips produced by the SMT process are clean, the surface is very clean and there are no impurities or stains. However, if the inferior LED strips produced by the hand soldering process are cleaned, the surface will remain stained and cleaned, and flux and tin residue will remain on the surface of the FPC.

4. Compare the packaging.

Regular LED strips will be packaged in anti-static coils, usually 5 meters or 10 meters, and then sealed with anti-static moisture-proof bags. The low-quality LED light bar will use the recycling coil tray because of cost-saving, and then there is no anti-static moisture-proof packaging bag. Carefully observe the coil tray, and it can be seen that the appearance has traces and scratches left when the label is removed.

5. Compare the label.

Regular LED strips and reels will have printed labels on them instead of printed labels. Low-quality led strips labels are printed, and specifications and parameters are not uniform.

6. Compare attachments.

Regular LED strips will be accompanied by instructions for use and light bar specifications, as well as LED strip connectors or decks; these are not available in low-quality LED strip boxes. Some manufacturers can still save the province after all.

led strip light
led neon light

#4. The flexible LED strip technical parameters

1. Voltage:

This refers to the input voltage of the LED light bar. The commonly used specifications are DC 12V, and some are 24V. Working voltage: DC12V Power: 14.3 watts per meter, 18.2 watts per meter, optional.

2. Color temperature:

It refers to heating a standard black body. When the temperature rises to a certain extent, the color begins to change from deep red – light red – orange yellow – white – blue, and when the color of a light source is the same as that of the black body, we will call the absolute temperature of the black body at that time. Is the color temperature of the light source.

In general, color temperature is not an indicator for evaluating LED strips, but many foreign customers will make a special request because of the environment.

The color temperature of the light source is different, and the light color is different:

The color temperature is below 3300K, and the light color is reddish to give a warm feeling; there is a steady atmosphere, a warm feeling, and is a warm color temperature.

The color temperature is in the middle of 5000–6000K. There is no obvious visual psychological effect in this color tone, and there is a refreshing feeling; so it is a “neutral” color temperature.

The color temperature is over 6000K, and the light color is blue, giving people a feeling of coldness, which is called cool color temperature.

Under normal circumstances, 7500K (cold white bluish) / 6500K (white) / 3500K (warm white and yellow).

3. Brightness:

The basic unit of luminous intensity, the cd is one of the basic units of the International System of Units.

Generally, different colors of LED strips have different luminous intensities. The common unit is mcd, which is millicandela. The higher the value, the greater the luminous intensity, that is, the brighter. This is an important indicator for assessing the brightness of LED strips. The higher the brightness requirement, the more expensive the strip. This is because high-brightness LED chips are expensive, and the higher the brightness, the more difficult the package is.

4. Beam angle:

This refers to the angle of illumination of the LED elements on the LED strips. Generally, the illuminating angle of the SMD LEDs (ie, SMD components) is 120 degrees. The larger the illumination angle, the better the astigmatism effect, but the relative brightness of the luminescence is correspondingly reduced. The angle of illumination is small, the intensity of the light is up, but the range of illumination is reduced. Therefore, another important indicator for evaluating LED strips is the angle of illumination. There are some unscrupulous manufacturers on the market. In order to increase the brightness of the light to earn higher profits, the angle of illumination is deliberately reduced. If you are not careful, you will buy such shoddy components.

led neon light


Through the above knowledge, we hope to help you understand the knowledge of led strips, and choose the right led products, if you have other questions, please contact us: 

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