Do you know how to make the small spacing LED display never black?As we all know, do you know how to make the small spacing LED display never black? The LED display screen is not an ordinary electrical appliance formed at one time in the factory, but a product made on site according to the customer's use requirements and installation environment. The failure rate is much higher than that of other electrical appliances. Therefore, it has high requirements for the rigor of on-site production personnel and after-sales requirements of the manufacturer.In recent years, the application of small spacing LED display screen is becoming more and more popular. With the unique advantages of display effect, its application places range from ordinary conference room, monitoring room and Exhibition Application to National Conference Center, monitoring center, CCTV and large-scale events. Such as G20 meeting, Zhu rihe military parade and Tianjin National Games, the figure of small spacing LED display screen is everywhere.
However, as a new technology and high-precision equipment, in addition to the excellent display effect, the user needs are also accompanied by stability considerations, because once the black screen appears in the main venue, it will have a significant international impact and even political impact, such as the 5-ring to 4-ring of the Tianjin National Games.Application field analysis of small spacing display screenAs a new generation of indoor professional display panel, small spacing LED has formed the most direct impact on the traditional DLP. In other words, small spacing LED has actually formed a technical replacement for DLP in product application. But this substitution is not a simple one-to-one. There are still great application differences between small spacing LED display and DLP, so the technical selection of screen is particularly important for different projects.
Therefore, when the small spacing LED is used as the main screen of the venue, its stability assessment is the top priority, and the first one is that the screen cannot be black.Analysis of the reasons for never black screenBecause of this demand, we deeply analyze the causes of black screen, so as to fundamentally eliminate the hidden dangers of black screen and truly never black screen. The display screen is an electronic device, the internal control card chip is FPGA, and there is no operating system, so the reasons for the black screen can be classified into two parts, one is device failure and the other is cable failure.
1: Equipment failureEquipment failure mainly occurs in two devices: receiving card and switching power supply.A: Receiving card
There are many devices on the receiving card. An ordinary receiving card integrates two gigabit network communication interfaces, 120P light board drive interfaces, SDRAM, flash, etc. with more than 10000 solder joints. Due to the inductive load of LED, its working environment is relatively complex. In order to pursue ultra-thin, some manufacturers sacrifice internal heat dissipation space and use mini cards. Their electronic devices have many contacts, complex electromagnetic environment and internal high thermal environment, resulting in reduced working stability. An accidental capacitor fault may cause abnormal screen display.B: Switching power supply failureThe LED display screen is an inductive load, and the output load changes with the picture, which has a great impact on the internal devices. In addition, there are many internal capacitors in the switching power supply. In order to reduce the use cost, some manufacturers use the switching power supply with automatic fan cooling. Because both capacitors and fans have a short service life, it has become the most frequent inducement of switching power supply faults, and the black screen fault caused by power supply fault ranks first in the whole device and equipment.
2: Cable failureCable faults are mainly divided into external connecting cables, such as cables that provide power and signals to the screen, and internal cable faults, such as internal DC power line, internal gray line, etc.A: External cable
Among the external cables, the signal cable has the highest failure rate and the greatest impact. The signal cable commonly used for the display screen is CAT5e cable, which is difficult to ensure the stability of signal communication due to material construction and other factors, especially the butt joint of 2-end crystal head, with poor vibration resistance.B: Internal cableThe internal cables are mainly gray cables, as shown in the figure below. Most of the gray ribbon cables are made by cold pressing. After many times of plugging, the contacts are easy to have poor contact, and even the gray ribbon cable is broken seriously. Therefore, the internal cable fault has the highest incidence of all cable connection faults.
Coping strategies of never black screenThe above analyzes several reasons for the black screen. We will apply the right medicine to the case, shield the above problems from the design end, and fulfill our commitment to customers and users - never black screen.One of the sharp tools to never black screen: no receiving card
Compared with the traditional receiving card design scheme, our company adopts the scheme without receiving card to highly integrate the products,The special chip with higher integration is designed on the adapter board. The chip integrates gigabit network communication, FPGA, SRAM, flash, MCU, etc. in the conventional receiving card. It has changed from seven ICs to one IC, which is highly integrated, reduces the solder joint connection by 80%, reduces the failure rate of electronic devices from the front end, and then improves the system stability.Never black screen sharp weapon 2: no flat cable, connector hard connection
Compared with the flat wire connection just now, there is no connecting cable inside, and all transmission is carried out through PCB and connector, which avoids hidden dangers such as multiple plug-in fatigue of cables and poor contact caused by conventional cold pressing from the design end.Never black screen Sharp Weapon 3: dual power supply
As mentioned above, switching power supply failure is the first among device failures, so dual power supply backup is generally adopted for high-end applications. At the same time, the switching power supply designed by our company has the function of automatic current sharing, that is, two power supplies are output at the same time, which can reduce the workload of the power supply, prolong the service life of the power supply, avoid the power grid impact caused by the cold switching of the power supply, display jitter or third harmonic caused by equipment restart, and monitor the power supply status in real time at the software end, It can also be replaced quickly during maintenance to eliminate faults.
Never black screen Weapon 4: loop designAccording to the level of on-site demand for signal stability and cost budget, our products can complete four levels of backup. The two most important levels of backup are dual interface and dual loop, and dual interface and four loop. Dual interface and dual loop are generally used for TV stations, while dual interface and four loop are used for live broadcasting, national live conference, etc.Double interface and double loop of never black screen loop design
As shown in the figure above, two independent signal loops are composed of dual signals, which can ensure that when one loop fails, the other loop can be switched immediately and the switching time can be reduced 0.1ms. For the hot standby places where some TV stations require power interfaces, power connectors can be added to realize dual power supply and dual signals on the screen. At the splicer end, two independent duplicate signals can be output to two transmission boxes through the backup board card.Double interface four loop design of never black screen loopThe backup level is the highest level, that is, the four input ports of the signal can work normally as long as one is normal. This backup mode is adopted for the main screen of the venue of the Guangzhou Asian Games. Of course, this backup mode will increase the cost of front-end equipment, which is usually more than 4 times higher than the conventional configuration. The above is the solution that the small spacing LED display screen will never be black. I hope it can help you.