Factors that cause LED display failure

 80% of LED display failures are caused by the following factors: AC power distribution wiring harness, terminals, connectors, signal and low-voltage DC connection wiring harness and connectors, switching power supply modules, fans, plastic shell components. If these interfaces, cables, power supplies, and bottom shells are not selected properly, the LED display screen will be black or partially black, blurred, mosaic, no signal, etc. These are also very difficult to maintain, so we pay attention to them in the production process to reduce the failure rate.

80% of the remaining failures are caused by the following reasons: solder joints, capacitors, terminals, LED lights on the PCBA, water leakage and dust accumulation caused by insufficient protection level of the cabinet, corrosion of the hardware hardware of the leaking screws, and the control board card. These reasons will cause the LED display to have blind lights or highlight, one or more lines are not bright, lack of color, etc., if there is a problem with the control card or software, it will cause the image to display abnormally. The outdoor LED display must be designed in strict accordance with the testing standards, waterproof and dustproof, wind and high temperature resistance, otherwise it is prone to various failures, and even the entire LED display screen will be scrapped. In addition, the operator of the display screen should master the relevant basic knowledge and have good usage habits. Coupled with professional maintenance personnel, the failure rate can also be reduced to a certain extent.

    LED display fault detection

    1. Resistance detection method, adjust the multimeter to the resistance mode, detect the resistance value of a certain point of a normal circuit board, and then detect the same point of another same circuit board to test whether the resistance value is different from the normal resistance. If they are different, the scope of the problem is determined.

    2. Voltage detection method: adjust the multimeter to the voltage range, detect the ground voltage of a certain point of the circuit suspected of having a problem, and compare whether it is similar to the normal value, otherwise the scope of the problem is determined.

    3. Short-circuit detection method, set the multimeter to the short-circuit detection gear (some are diode voltage drop gears or resistance gears, usually with alarm function) to detect whether there is a short-circuit phenomenon, and the short-circuit should be solved first to prevent it from burning Other devices. This method must be operated when the circuit is powered off to avoid damage to the meter.

    4. Voltage drop detection method, adjust the multimeter to the diode voltage drop detection gear, because all ICs are composed of many basic single components, but are miniaturized, so when there is a current passing through a pin of it, There will be a voltage drop across the pin. Generally, the voltage drop on the same pin of the same type of IC is similar. According to the voltage drop value on the pin, it is necessary to operate with the circuit power off. This method has certain limitations. For example, if the tested device is high-impedance, it cannot be detected.

    Failure and solution

1. The whole screen is not bright or there are squares

  an examination:

　　 1. Whether the control host is in good condition

　　2, turn on the communication line, whether it is plugged in

　　3. Is the sending card inserted?

　　4. Whether the data line between the multimedia card and the sending card of the capture card is well connected

　　 5. Whether the position of the receiving card JP1 or JP2 switch is correct

　　Debug:

　　1, turn on the host

　　2, plug in the communication line

　　 3. Reinsert the sending card

　　4. Connect the multimedia card and the capture card, and the data line between the sending card

　　 5. Adjust the JP1 JP2 switch position

2. The control system cannot be found every time the LED studio is started

  problem:

　　1, the signal collection line from the COM port to the data sending card

　　2, there is no connection or the 2COM port of the computer itself is broken