In order for the LED display to be used normally, some factors that will affect the LED display must be excluded. Due to the lack of knowledge in this area, the LED display will retire early. Like other items, the LED display screen will inevitably encounter problems and precautions of one kind or another in use. When using a full-color LED large screen, the following eight problems may affect the use of the large screen. Understand the precautions for the use of LED display screens, and correct use can prolong its service life. Let me tell you about YONGS LED display specifically.
1. Heat dissipation design: LED will generate heat when working, and if the temperature is too high, it will affect the attenuation speed and stability of the LED. Therefore, the heat dissipation design of the PCB board and the ventilation and heat dissipation design of the box will affect the performance of the LED.
2. Mixed lights: LEDs of the same color with different brightness levels need to be mixed, or inserted according to the light-insertion diagram designed by the discrete law to ensure the consistency of the brightness of each color on the entire screen. If there is a problem in this process, the local brightness of the large screen will be inconsistent, which will directly affect the display effect of the large LED screen.
3. Design current value: The nominal current of the LED is 20mA. It is generally recommended that the maximum use current should not exceed 80 percent of the nominal value. Especially for large screens with small dot spacing, the current should be reduced due to poor heat dissipation conditions. value. According to experience, due to the inconsistency of the attenuation speed of red, green and blue LEDs, the current values of blue and green LEDs are reduced in a targeted manner to maintain the consistency of white balance after long-term use of the large screen.
4. Drive circuit design: The arrangement of the drive IC on the drive circuit board on the large screen module will also affect the brightness of the LED. Since the transmission distance of the output current of the driver IC on the PCB is too long, the voltage drop in the transmission path will be too large, which will affect the normal operating voltage of the LED and reduce its brightness. We often find that the brightness of the LEDs around the large screen module is lower than that in the middle, which is the reason. Therefore, in order to ensure the consistency of the brightness of the large screen, it is necessary to design the distribution diagram of the driving circuit.
5. Control the verticality of the lamp: For the in-line LED, there must be enough process technology to ensure that the LED is perpendicular to the PCB board when passing through the furnace. Any deviation will affect the brightness consistency of the LEDs that have been set, and color blocks with inconsistent brightness will appear.
6. Welding control: When the LED does not light up on the large LED screen, there is often more than 50 percent probability that it is caused by various types of virtual welding, such as virtual welding of LED pins, virtual welding of IC pins, and virtual welding of pins and mothers. Welding etc. The improvement of these problems needs to strictly improve the process and strengthen the quality inspection to solve. The vibration test before leaving the factory is also a good inspection method.
7. Temperature and time of wave soldering: The temperature and time of wave soldering must be strictly controlled. It is recommended that the preheating temperature be 100 degree ± 5 degree , and the maximum temperature should not exceed 120 degree . The temperature is 245 degree ±5 degree , and the welding time is recommended not to exceed 3 seconds. Do not vibrate or impact the LED after passing through the furnace until it returns to normal temperature. The temperature parameters of the wave soldering machine should be checked regularly, which is determined by the characteristics of the LED. Overheating or fluctuating temperature will directly damage the LED or cause hidden dangers to the quality of the LED, especially for small-sized round and oval LEDs such as 3mm.
8. Anti-static: LED large screen assembly factories should have good anti-static measures. Special anti-static ground, anti-static floor, anti-static soldering iron, anti-static table pad, anti-static ring, anti-static clothing, humidity control, equipment grounding (especially the foot cutter) are all basic requirements, and should be checked regularly with an electrostatic meter .
