LED display failure analysis and processing methods:
 
     For the LED display industry, the medium-sized companies, Tung & Poor's science and technology in the course of many years of development, forming its own technical standards, but also deal with the problem have their own methods, but living in the big family of LED display enterprises, most enterprises the problems encountered are not the same, the following is an LED display problems fault analysis and processing methods:
     A. Output problems
     1, detection output interface to the signal output of the circuit IC is connected or short-circuit.
     2, detection of the clock latch output signals are normal.
     3, testing the last one driver IC cascaded between the output data port is the data port and the output interface to connect or if short-circuit.
     4, the output signal if there is a mutual short-circuit or short circuit to ground.
     5, check the output cable is good.
     B. All bright line or a few lines from time to time does not shine
     One, testing between the 138-4953 line is open circuit or cold solder joint, short-circuit.
     C. The entire board does not shine
     1, check power supply and signal cable is connected.
     2, check whether the test card to identify the interface, the test card is no identified red light flashing, check whether the light panel test card with the power ground, or light board interfaces with the signal and ground lead to short-circuit does not recognize interface. (Intelligent Test Card)
     3, testing whether 74HC245 cold solder joint short circuit, corresponding to 245 on the enable (EN) signal input and output pin is cold solder joint or a short-circuit to other circuits.
     Note: The main power and check the enable (EN) signals.
     D. Oblique scan at the point when the law does not shine the interlaced display overlapping
     1, check A, B, C, D input Koudao 245 whether there are disconnected or cold solder joint between the short-circuit.
     2, detection of 245 corresponds to A, B, C, D and the 138 output is open circuit or cold solder joint between the short-circuit.
     3, test A, B, C, D between the various signals whether the short-circuit or a signal and ground short-circuit.
     Note: The main line of the signal detection ABCD.
     E. Show confusion, but the output signal of the next one plate and normal
     1, testing the corresponding STB latch 245 and drive IC output of the latch side or the signal is short-circuit is connected to other lines.
     F. There is a bright full-time or a few columns are not bright
     1, in the module found in control of the column pin, measuring whether the driver IC (74HC595/TB62726,,,) output connection.
     G. There is a single-point or in a separate highlighting, or highlight the entire row and not controlled
     1, check whether the column is with the power to short-circuit.
     2, testing whether the bank's positive short-circuit power supply.
     3, the replacement of its driver IC.
     H. Show confusion, the output is not normal
     1, testing whether the clock signal CLK latch short-circuit STB.
     2, testing whether there are 245 clock CLK input and output.
     3, testing whether the short-circuit the clock signal to other circuits.
     Note: The main test clock and latch signals.
     I. Showing lack of color
     1, detection 245 of the color of the data whether there are input and output.
     2, testing the color of the data signal is short-circuit to other circuits.
     3, testing the color level between the driver IC with data port whether there is open circuit or short circuit, cold solder joint.
     Note: You can use the voltage detection method is easier to find problems, test data port is different from the normal voltage to determine the trouble spots.
      J. When full-bright single-point or multi-point (no law) does not shine
     1, find the module corresponding to the control of foot measurement of whether the Bank's short-circuit.
     2, the replacement module or a single lamp.
     K. Line scan, two lines or a few lines (usually a multiple of 2, there is regularity) at the same time lit
     1, test A, B, C, D is short-circuit between the various signals.
     2, testing whether the 4953 output with other output short-circuit.