I do not know you have not encountered such a situation, when the assembled power LED display, the screen suddenly appeared yin and yang face - that half light half dark. Sometimes well-defined two areas, sometimes only a gradual transition from the Ming dimmed. The reasons for this situation may be caused by software or set up, it could be a problem with the lamp. Next ,, we have to pass a number of detailed tests to identify the problem and solve the problem.
   LED unit board Symptom test analysis:

    A, LED unit board does not shine

    (1) whether the normal check 595 chip.
    (2) check the upper and lower module corresponds to whether it is turned on foot in order.
    (3) check the output pin to 595 pin module is switched on.

    Second, the cell plate line is not bright

    (1) check 138 is normal.
    (2) whether the investigation foot line and 4953 feet through output.
    (3) check whether the 4953 high.
    (4) 4953 to check whether hot or burned.
    (5) 138 4953 to check whether there through foot control.

    Three, LED electronic display unit board section piece black

    (1) If there is a continuous longitudinal direction of a few boards does not light, check the power supply is normal in this column.
    (2) If a few consecutive plate transverse direction is not bright, cable examination was normal and abnormal cell plate cell plate connection is turned on; or chip 245 is normal.
    
    Four, LED unit board lack of color

    (1) whether there is output data 245 R.G check.
    (2) to check whether the normal output of 595 feet and abnormal input 595 feet through.

    Five, LED electronic display the entire screen (black)

    (1) detecting the power is energized.
    (2) computer monitor is protected or display area is black or pure blue. (Synchronous screen)
    (3) detection of communication cable is plugged in, with or without wrong. (Synchronous screen)
    (4) The synchronous screen detection sending card and receiving card communication whether the flashing green light.

    LED unit board failure encountered by some of the basic steps necessary to detect, can help to quickly find the cause of the problem, but also to remind the operator during the installation of the ordered connection Follow the steps to ensure the normal display LED display .