How to Quickly Solve the Heat Dissipation Problem of LED Display Screen

Manufacturing industry has always been known as the "mother of industry". Looking at the development of the global LED display industry, China is also a well deserved LED display manufacturing country. Even in these years of development, China's LED display screen is rewriting the world led display screen industry pattern. In this process, not only the application end products bear the brunt, but also the supporting products of the display screen play a very important role. As we all know, China's LED display industry started relatively late, and has made remarkable achievements in catching up in recent years. Moreover, with the gradual release of national favorable policies and market potential, led supporting equipment has also accelerated the upgrading and optimization of the industry.At present, the supply chain of supporting products of LED display screen in China is very extensive and complete. There is a systematic industrial chain from box to screw. And there are some enterprises with innovative consciousness and strong application R & D ability. However, generally speaking, the total number of LED supporting enterprises in China is not large. The development and broad market of LED display screen in recent years are gradually attracting more supporting manufacturers to join the industrial chain of LED display screen. The competition in the market is gradually increasing. At the same time, it also enhances the competitive awareness of enterprises, strengthens the close cooperation with LED display manufacturers in product R & D, and provides LED display manufacturers with more technical content and more competitive products. It promotes the development of the whole LED display screen in technology and product innovation. With the development of supporting enterprise technology and the improvement of quality, it also provides a strong backing for LED display screen and jointly promotes the progress of the industry.With the gradual expansion of the application scenario of LED display screen, the product demand of customers has also changed. When choosing products, they tend to meet their diversified and personalized needs. Among them, LED display box occupies an important position in the whole supporting equipment. LED display box materials are widely used, generally iron box, high-end can use die-casting aluminum, stainless steel, carbon fiber, magnesium alloy and nano polymer materials. The box plays an important role in the application of the whole display terminal. Protect the electronic components inside from the interference of the external environment, and have a good protective effect on the protection of components. At the same time, because it works in a high temperature environment, good box material selection can reduce the impact of service temperature on components in the process. Since the display screen is composed of multiple boxes spliced, the selection of box material will also affect the flatness of LED display screen, so the role of box in the display screen is also obvious.In recent years, with the development of display technology, the requirements of LED display manufacturers for box are also gradually improved. LED display supporting manufacturers have also launched carbon fiber LED display box, magnesium alloy LED display box, nano polymer LED display box, etc. through their own technical R & D and innovation. From the original iron box, to the die-casting aluminum box and the current carbon fiber box, the innovation and progress of LED display screen are inseparable from the efforts of manufacturers as supporting products.In the whole production cost of LED display screen, the cost of frame is about 3% 5%. Although the proportion is not high, it largely determines the appearance and grade of LED display screen. Therefore, as a manufacturer of LED display frame, if it doesn't make great efforts in product R & D, it can't show high-grade effect. Industrial aluminum profile is a common material in social production. It is widely used in aviation, construction, condenser, automobile parts and LED application products. LED display aluminum profile has a wide range of applications, and its market share has reached a high share. It has become an important new material for the frame of LED advertising display screen. This is also bringing new business opportunities to the development of LED display supporting equipment manufacturers. GEKO gold frameThe surface of the traditional LED display frame is a conventional black electrostatic powder spraying process. Through the R & D and process improvement of LED display frame enterprises in recent years, electrophoretic silver and electrophoretic gold frames have been introduced in the market, which changes the situation that the LED display frame used only black in the past. It has formed differentiation in appearance, improved the grade of products, and received good feedback from end users. In addition to color, there are also many innovations in product structure. For example, a number of products newly developed by Jike application have won national patents, widely praised by the market, and have made good achievements in the field of LED display supporting products.In the field of LED display matching, connector is a small and precise device, and its quality is the focus of LED display matching equipment manufacturers. There is no absolute advantage in the connector industry at this stage. Connectors can also achieve high-end adaptation in some subdivided fields. Due to the different needs of each customer, the LED display supporting production enterprises have developed private customized products by using the company's professional R & D team according to the market demand. Through the R & D and production of supporting enterprises, it can save about 5% of the cost for display enterprises in the current competitive market. Moreover, through technological innovation, these connectors realize board to board link, which greatly facilitates the disassembly and assembly process of LED display. In recent years, led rental display screen has sprung up. These technological innovations have effectively solved the problems of inconvenient installation and difficult maintenance. This is also the future development direction of the connector.The above conclusion is that the LED industry is developing rapidly, and there are countless large and small LED display manufacturers in China. This situation of oversupply gradually highlights the cruel face of industry competition. The fall of some LED manufacturers in recent years indicates that the LED industry will face a major reshuffle again. Of course, if we want to improve efficiency in production speed, we must have technology as a strong backing. The future development trend of LED supporting field will be more and more convenient.When the market competition situation is not optimistic, win the market of product R & D and innovation peers with speed, such as battlefield and the law of the jungle. The success of an enterprise, in addition to having a correct development direction, must have a certain core competitiveness. In order to maintain competitiveness and occupy market share in the same industry, enterprises must constantly develop new products and quickly push them to the market to meet the changing market demand. If new products cannot successfully occupy the market, enterprises will lose market share and eventually lose profitability and competitive advantage.

On the occasion of the 99th anniversary of the founding of the party, in today's rapid economic prosperity, the continuous development of our science and technology, more and more LED displays are applied in various fields, and more benchmarking projects have been established. For applications requiring high stability of practical effects, the large display screen of Party and government organs represents the wind vane of high-end indoor large screen display system. Here's how to select a large screen in different application scenarios to achieve better display effect.Service hallSMD encapsulated led HD display screen has MTSC broadcast level color gamut to restore the real color. The screen display color gamut is ultra wide and the color is richer, reaching the broadcast level standard; After point by point brightness and chroma correction, the brightness and chroma of the screen remain highly consistent without secondary compensation, and the color is high fidelity; It adopts the international leading point-by-point correction technology, and uses the advanced green restoration and skin color restoration functions to fully adapt to the human eye's perception of color, which has a better display effect on the hall display and public information publicity.Conference room and lecture hallThe indoor conference room and lecture hall can use LED display with small point spacing. The voury Zhuohua micro spacing LED display adopts unique intelligent brightness adjustment technology, with brightness of 0-1200cd / m2 adjustable, which can automatically adjust the brightness according to the light and dark changes of the surrounding environment, so as to ensure that the picture is still comfortable and soft in various indoor brightness environments; Small dot spacing makes the picture more delicate and clearer.Exhibition hall and exhibition hall publicity on each floorFor hall display and public information publicity, the display screen needs to have an ultra wide viewing angle. VW micro spacing LED display screen has an original wide viewing angle technology, with an ultra wide viewing angle 170 degrees in both vertical and horizontal directions, larger display coverage, no dead angle and color deviation, and the image is always perfect and seamless. Moreover, it has a variety of installation methods to adapt to any site. It can be landed, hoisted, inlaid and hung on the wall. It can design the best installation scheme for users according to the situation of the installation site, so as to achieve the perfect unity between the display screen and the surrounding decoration. Meet the needs of the hall display.fqj

The epidemic in the United States is still "burning", and there is no slowing trend at all. However, in order to restart the U.S. economy, the U.S. NBA professional basketball game opened again in the early morning of July 23. On the first day, eight basketball teams from the United States participated. Due to the epidemic, the basketball game has been postponed for a long time, and some star players have all arrived. This is an empty game. In order to create a lively atmosphere for the audience, the careful staff also arranged a number of huge LED display screens on the stadium to let the photos of the fans appear on the display screen, so as to make it easier for the on-site players to participate in the game.After watching the whole NBA warm-up game, there are really few highlights. On the contrary, I feel that an NBA game is not as good as China's CBA game. First of all, players may not play basketball for a long time, and the state of the court game is very general. The court layout can be described as poor. The court space is relatively small, which is very different from the regular NBA home court. In addition, the biggest hard injury to the layout of the whole stadium is the huge LED display screen.In order to create an atmosphere for players to play in the stadium, the staff set up a huge LED display screen at the edge of the stadium. When players play, the huge LED display will beat the slogan of NBA semi-finals, and there will be pictures of fans applauding and cheering. This is cloud refueling. Players complete a layup. It is strange that the huge LED display screen of the stadium plays the cheering scenes of other teams, which is really embarrassing. We can see the importance of a high-quality huge LED display screen.The use of the huge LED display screen of Riad smart display improves the on-site experience of the fans, and the use of the new scoreboard can easily improve the level of the venue. At the same time, the LED display screen has many functions, such as wonderful moment capture, strange lens playback, real-time live broadcast synchronization, competition information broadcasting, timing and integral statistics, advertising broadcasting, etc. coupled with perfect picture quality and sound equipment, it makes the scene more competitive atmosphere and shocking.Nowadays, events have been held more and more frequently in large and small stadiums, and the quality of LED display screens installed in related stadiums is particularly important. To judge the quality of huge LED display screen, we need to look at the technical indicators of three major keywords. They are flatness, viewing sight distance and high pixel.1. The flatness of LED display screen, local unevenness of the screen body, dead angle in viewing angle, or stretching and fracture of the screen. The simple method is to place the side of the long steel ruler at any position on the screen of the display screen, and measure the gap between the side of the steel ruler and the screen of the display screen with a feeler gauge.2. Viewing sight distance: the gymnasium should pay attention to the installation of LED display screen. The distance between spectators and display screen in the venue should meet the sight distance of most spectators. The sight distance of LED display screen is about the distance that the audience can see the characters of LED display screen clearly under normal conditions.3. With high pixels, the pixel out of control rate of the display screen of domestic and foreign stadiums (indoor and outdoor stadiums, large and small comprehensive stadiums) shall not be greater than two thousandths, and shall be distributed discretely. In order to eliminate picture particles, avoid moire lines during shooting and make the broadcast picture clearer, high pixels of LED display screen are required.fqj

1. LED brightnessThe brightness of LED is generally expressed by luminous intensity, and the unit is candela CD; 1000ucd (micro candela) = 1 MCD (millicandela), 1000mcd = 1 CD. The light intensity of a single LED for indoor use is generally 500ucd-50 MCD, while the light intensity of a single LED for outdoor use is generally 100 mcd-1000 MCD, or even more than 1000 MCD.2. LED pixel moduleThe LEDs are arranged into a matrix or pen segment and prefabricated into standard size modules. 8 * 8 pixel module and 8-character 7-segment digital module are commonly used for indoor display screen. The outdoor display pixel module has 4 * 4, 8 * 8, 8 * 16 pixels and other specifications. The pixel module for outdoor display screen is also called collecting tube bundle module because each pixel is composed of more than two LED tube bundles.3. Pixel and pixel diameterEach LED light emitting unit (point) in the LED display screen that can be individually controlled is called a pixel (or pixel). Pixel diameter refers to the diameter of each pixel, in millimeters. For indoor display screen, generally one is a single LED with a circular shape. There are 3.0, 3.75, 5.0, 8.0 and so on, among which 3.75 and 5.0 are the most common. In the outdoor environment, in order to improve the brightness and increase the sight distance, one pixel contains more than two cluster LEDs; Since more than two cluster LEDs are generally not circular, the pixel diameter of solid outdoor display screen is generally expressed by the average distance between two pixels: 10, 11.5, 16, 22, 25.4. Point spacing, pixel density and information capacityCenter distance or dot pitch of two pixels of LED display screen; The number of pixels per unit area is called pixel density; The amount of display content per unit area is called information capacity. The essence of the three is to describe the same concept: the point spacing reflects the pixel density from the distance between two pixels, and the point spacing and pixel density are the physical properties of the display screen; Information capacity is the unit of information carrying capacity of pixel density. The smaller the point spacing, the higher the pixel density, the more information capacity, and the closer the distance suitable for viewing. The larger the point spacing, the lower the pixel density, the less the information capacity, and the farther the distance suitable for viewing.5. ResolutionThe number of rows and rows of LED display pixels is called the resolution of LED display. Resolution is the total number of pixels of a display screen, which determines the information capacity of a display screen.6. LED panelThe LED pixel modules are assembled and arranged into a matrix according to the actual size, and equipped with special display driving circuit, DC regulated power supply, software, frame and external decoration to form an LED display screen.7. GrayscaleGrayscale refers to the degree of light and shade change of pixels. The grayscale of a primary color generally has 8 levels to 1024 levels. For example, if the gray level of each primary color is 256, the display color of the dual primary color screen is 256 256 = 64K color, also known as 256 color display screen.8. BicolorNowadays, most color LED displays are dual primary color screens, that is, each pixel has two LED tube cores: one is red tube core and the other is green tube core. When the red light tube core is on, the pixel is red, when the green light tube core is on, the pixel is green, and when the red and green tube cores are on at the same time, the pixel is yellow. Red and green are called primary colors.9. Full colorRed green double primary color plus blue primary color, three primary colors constitute full color. Because the blue tube and pure green tube core constituting full-color are more expensive, there are relatively few full-color screens at present.

prefaceThe LED display box has self-determined size, high structural strength, good flatness and easy splicing. Generally speaking, the size of Maipu Guangcai LED electronic screen will not be limited. So, can the size of LED electronic display really be enlarged at will? In fact, it can not be tolerated. We can explain it from the following aspects.01. Price and cost of LED displayAs for the price of electronic screen, the price of LED screen was maintained at 351 square meters several years ago. With the more extensive use in the past two years, the price is now almost maintained at 7000 or 8000 per square meter. Of course, this includes its steel structure, accessories, control card, computer, and so on! Generally speaking, it can be infinitely enlarged, but because of this price, most users can't afford it.02. Visual viewing effectThe farther the display is viewed, the larger the screen must be. Similarly, the closer the viewing distance, the smaller the screen must be. For example: our common indoor LED display screen, under normal circumstances, the viewing distance is a few meters. If it is far, it is at most 20 or 30 meters. Therefore, the area of indoor screen will not be too large, and most of them will be kept within 60 square meters. For the LED outdoor display screen, the viewing distance will be relatively far, generally from more than ten meters, so the area of Maipu brilliant display screen will be relatively large, usually within 10-100 square meters.03. Installation location and environmentThere is no doubt that the indoor environmental space location is relatively limited. For those outside the room, if there is not enough space and position to support, any screen of the display screen will be subject to relatively large nature, so the screen can be enlarged at will here.04. After sales serviceOf course, there is also a major problem that can not be ignored, that is, when the Maipu brilliant LED electronic display is enlarged at will, the after-sales service will become more and more difficult. Once a problem occurs, the relevant maintenance and troubleshooting is quite troublesome, which is a huge test in terms of manpower, money and time.fqj

In practical application, improving the heat dissipation of LED display screen can not only effectively improve the efficiency of heat dissipation of LED display screen, but also save power, which is more conducive to improving the service life of LED display screen.1. It is a common method to use a long-life and high-efficiency fan to strengthen heat dissipation inside the lamp shell. This method has low cost and good effect.2. Aluminum cooling fins are the most common way of heat dissipation. Aluminum cooling fins are used as part of the shell to increase the heat dissipation area.3. Aerodynamics, using the shape of the lamp shell to produce convective air, which is the lowest cost method to strengthen heat dissipation.4. Surface radiation heat dissipation treatment: the surface of the lamp shell is treated with radiation heat dissipation. The simpler thing is to apply radiation heat dissipation paint, which can bring the heat away from the surface of the lamp shell by radiation.5. Integration of heat conduction and heat dissipation -- the application of high heat conduction ceramics. The purpose of heat dissipation of lamp shell is to reduce the working temperature of LED HD display chip. Because the expansion coefficient of LED chip is very different from that of our common metal heat conduction and heat dissipation materials, the LED chip cannot be directly welded to avoid high and low temperature thermal stress damaging the chip of LED display.6. The heat conduction tube is used for heat dissipation, and the heat is guided from the LED display chip to the shell heat dissipation fin by using the heat conduction tube technology.7. The thermal conductive plastic shell is filled with thermal conductive materials during injection molding of the plastic shell, so as to increase the thermal conductivity and heat dissipation capacity of the plastic shell.It can be seen that the maturity and progress of LED display heat dissipation technology will be conducive to its concept of saving and environmental protection. LED electronic display manufacturers have a variety of methods to improve the heat dissipation of LED display in the production of LED display. There will be different considerations according to the power and place of use.

The LED display box has self-determined size, high structural strength, good flatness and easy splicing. Generally speaking, the size of Maipu Guangcai LED electronic screen will not be limited. So, can the size of LED electronic display really be enlarged at will? In fact, it can not be tolerated. We can explain it from the following aspects.01. Price and cost of LED displayAs for the price of electronic screen, the price of LED screen was maintained at 351 square meters several years ago. With the more extensive use in the past two years, the price is now almost maintained at 7000 or 8000 per square meter. Of course, this includes its steel structure, accessories, control card, computer, and so on! Generally speaking, it can be infinitely enlarged, but because of this price, most users can't afford it.02. Visual viewing effectThe farther the display is viewed, the larger the screen must be. Similarly, the closer the viewing distance, the smaller the screen must be. For example: our common indoor LED display screen, under normal circumstances, the viewing distance is a few meters. If it is far, it is at most 20 or 30 meters. Therefore, the area of indoor screen will not be too large, and most of them will be kept within 60 square meters. For the LED outdoor display screen, the viewing distance will be relatively far, generally from more than ten meters, so the area of Maipu brilliant display screen will be relatively large, usually within 10-100 square meters.03. Installation location and environmentThere is no doubt that the indoor environmental space location is relatively limited. For those outside the room, if there is not enough space and position to support, any screen of the display screen will be subject to relatively large nature, so the screen can be enlarged at will here.04. After sales serviceOf course, there is also a major problem that can not be ignored, that is, when the Maipu brilliant LED electronic display is enlarged at will, the after-sales service will become more and more difficult. Once a problem occurs, the relevant maintenance and troubleshooting is quite troublesome, which is a huge test in terms of manpower, money and time.fqj

1. The display screen does not work and the green light of the sending card flashes (made into retractable type)Fault cause: the panel is not powered; The network cable is not connected properly; The receiving card has no power supply or the power supply voltage is too low; The sending card is broken; The signal transmission intermediate equipment is connected or faulty (e.g. function card, optical fiber transceiver).Troubleshooting: check and confirm that the power supply of the panel is normal; Check and reconnect the network cable; Ensure that the DC output power supply of the power supply is 5-5.2v; Replace the sending card; Check the connection or replace the function card (optical transceiver).2. The display screen does not work and the green light of the sending card does not flashFault cause: DVI or HDMI cable is not connected properly; The copy or expansion mode is not set in the graphics card control panel; The software chooses to turn off the power supply of the large screen; The sending card is not inserted in place or there is a problem with the sending card.Troubleshooting: check DVI cable connector; Reset the copy mode; The software selects to turn on the large screen power supply; Reinsert the sending card or replace the sending card.3. Prompt "large screen system not found" at startupFault cause: the serial port cable or USB cable is not connected with the sending card; Computer com or USB port is broken; The serial port cable or USB cable is broken; The sending card is broken; USB driver is not installed.Troubleshooting: confirm and connect the serial port cable; Replace the computer; Replace the serial port cable; Replace the sending card; Install new software or separate USB driver.4. Long strips of the same height as the lamp board are not displayed or partially not displayed or lack colorFault cause: poor contact or disconnection of flat cable or DVI cable (applicable to submarine Series); There is a problem with the former output or the latter input of the display light panel at the junction.Troubleshooting: reinsert or replace the cable; First determine which display module is faulty, and then replace it for maintenance.5. Some modules (3-6) are not displayedFault cause: power protection or damage; Poor contact of AC power line.Troubleshooting: check and confirm that the power supply is normal; Reconnect the power cord.6. The whole box is not displayedFault cause: 220V power supply line is not connected properly; There is a problem with network cable transmission; The receiving card is damaged; The hub board is inserted incorrectly.Troubleshooting: check the power supply line; Confirm to replace the network cable; Replace the receiving card; Reinsert the hub.7. Full screen flower point, picture shadow button movementFault cause: incorrect driver loader; The network cable of computer and screen is too long or of poor quality; The sending card is broken.Troubleshooting: reload the receiving card file; Reduce the length of network cable or replace it; Replace the sending card.8. The entire display screen displays the same content for each display unitFault cause: the display connection file was not sent.Troubleshooting: reset the screen file sending, and plug the network cable connected to the computer into the output port of the sending card near the indicator light when sending.9. The brightness of the display screen is very low and the displayed image is blurredFault cause: error in sending card program; The function card is not set correctly.Troubleshooting: restore the default setting of the sending card and save it; Set the minimum brightness value of display monitoring to more than 80.10. Shaking or ghosting of the whole screenFault cause: check the communication line between the computer and the large screen; Check the DVI line between the multimedia card and the sending card; The sending card is broken.Troubleshooting: reinsert or replace the communication line; Punch the DVI line for reinforcement; Replace the sending card.

Video processor is the witness and landmark equipment for the birth, growth and maturity of full-color LED display. Today, led special video processing equipment is also gradually maturing in this process. The quality of LED video processor directly affects the display effect of LED display.In general, LED video processor is a special video processor for LED. The task it needs to complete, in short, is to convert the image signal from the outside (such as Blu ray DVD, computer, HD playback box, etc.) into the signal acceptable to the LED display screen. In this process, the LED video processor generally needs to complete the following processing processes:1 Resolution specification conversion: Generally speaking, the signal resolution provided by image signal sources (such as Blu ray DVD, computer, HD playback box, etc.) has fixed specifications (refer to VESA, ITU, SMPTE and other standards), while the modular splicing display of LED display makes its resolution almost arbitrary. The video processor converts various signal resolutions into the actual physical display resolution of LED display screen.2 Color space conversion: the color gamut of LED display is very wide, while the color space of most image signals is relatively small (such as NTSC). In order to make the LED display have excellent image display effect, color space conversion must be carried out.3 Bit depth improvement: at present, the gray level of LED display has been increased to 16 bits and 17 bits, but most of the input signal sources are only 8 bits. Therefore, following the arrival of the era of high-definition display, the application of 10 bit or even 12 bit processing technology in video processor has become a general trend.4 Zoom: in the process of resolution specification conversion, the image needs to be scaled. Whether the resolution is increased or decreased, the complete image can be displayed on the screen.

Unit board fault:A. The whole board is not bright1. Check whether the power supply is connected to the signal line.2. Check whether the test card can identify the interface. If the red light of the test card flashes, it will not be identified. Check whether the lamp board is connected with the power supply and ground of the test card, or there is a short circuit between the signal and ground of the lamp board interface, so that the interface cannot be identified. (smart test card)3. Detect whether 74hc245 has faulty welding or short circuit, and whether the corresponding enable (EN) signal input and output pin on 245 has faulty welding or short circuit to other lines.Note: mainly check the power supply and enable (EN) signal.B. During oblique scanning, regular interlaced lines are not lit, and the display screen overlaps1. Check whether there is broken wire, faulty welding or short circuit between a, B, C and D signal input ports and 245.2. Check whether there is open circuit, faulty welding or short circuit between output terminals a, B, C and d corresponding to 245 and 138.3. Detect whether there is a short circuit between signals a, B, C and D or whether a signal is short circuited to ground.Note: it mainly detects ABCD line signal.C. When fully lit, one or more lines are not lit1. Detect whether the line between 138 and 4953 is open circuit, faulty welding or short circuit.D. During line scanning, two or more lines (generally multiple of 2, regular) are lit at the same time1. Check whether there is a short circuit between signals a, B, C and D.2. Check whether the 4953 output terminal is short circuited with other output terminals.E. Single or multiple points (irregular) do not light up when fully lit1. Find the control pin corresponding to the module and measure whether it is short circuited to the line.2. Replace the module or single lamp.F. When fully lit, one or more columns are not lit1. Find the pin controlling this column on the module and test whether it is connected to the output of the drive IC (74HC595 / TB62726,,).G. There is single point or single column highlight, or whole row highlight, and it is not controlled1. Check whether the column is short circuited to power and ground.2. Check whether the line is short circuited to the positive pole of the power supply.3. Replace its drive IC.H. The display is confused, but the signal output to the next board is normal1. Detect whether the STB latch output terminal corresponding to 245 is connected with the latch terminal of the drive IC or whether the signal is short circuited to other lines.1. The display is confused and the output is abnormal1. Detect whether the clock CLK latch STB signal is short circuited.2. Detect whether the clock CLK of 245 has input and output.3. Check whether the clock signal is short circuited to other lines.Note: it mainly detects clock and latch signals.J. Display out of color1. Detect whether the data terminal of the color of 245 has input and output.2. Detect whether the data signal of this color is short circuited to other lines.3. Check whether there is open circuit, short circuit and faulty soldering at the cascade data port between the driving IC of this color.Note: it is easy to find the problem by using the voltage detection method to detect whether the voltage of the data port is different from the normal one and determine the fault area.K. There is a problem with the output1. Check whether the line from the output interface to the signal output IC is connected or short circuited.2. Check whether the clock latch signal of the output port is normal.3. Check whether the cascade output data port between the last drive IC is connected with the data port of the output interface or short circuited.4. Whether the output signals are short circuited to each other or to the ground.5. Check whether the output cable is in good condition.Full screen fault:The whole screen does not light up (black screen)1. Check whether the power supply is powered on.2. Check whether the communication line is connected and whether there is a wrong connection. (step by step screen)3. The synchronization screen detects whether the communication green light of the sending card and the receiving card flashes.4. Whether the computer monitor is protected, or whether the display area is black or pure blue. (step by step screen)The whole unit board is not lit (black screen)1. If several consecutive boards are not lit in the transverse direction, check whether the cable connection between the normal unit board and the abnormal unit board is connected; Or whether the chip 245 is normal.2. If several consecutive boards are not lit in the longitudinal direction, check whether the power supply of this column is normal.The unit board does not light up1. Check whether the line pin is connected with the 4953 output pin.2. Check whether 138 is normal.3. Check if 4953 is hot or burnt.4. Check 4953 for high level.5. Check whether the 138 and 4953 control pins are connected.Unit board does not light up1. Check whether 595 is normal.2. Check whether the corresponding pins of the upper and lower modules are connected.3. Check whether the 595 output pin is connected to the module pin.Unit board lack of color1. Check whether 245 R.G data is output.2. Check whether the normal 595 output pin and the abnormal 595 input pin are connected.