LED display as a normal electronic goods will also be some problems, LED unit board is the most important part of the display will appear some questions, no one LED display unit board manufacturers to 100 percent license to ensure that the production of goods will never appear Problem, that LED display unit board failure how to deal with? Here to analyze some of the LED display unit board fault handling approach.
LED display unit board failure causes analysis and treatment methods:
First, the LED unit board the whole board does not shine:
1, check the power supply and signal lines are not connected.
2, check the inspection card is not able to identify the interface, check the card is not recognized red light flash, check the light board is not with the inspection card with the power or light board interface signal and ground short circuit can not identify the interface.
3, check the 74HC245 whether the short solder joint, 245 on the corresponding enable (EN) signal input and output pin is not Weld or short circuit to other lines.
Second, in the point of oblique scan, the regular interlaced flashing screen stack
1, check A, B, C, D signal input to 245 is not broken or Weld, short circuit.
2, check the corresponding A, B, C, D output and 138 is not between the short circuit or Weld, broken wire.
3, check A, B, C, D between the signals is not a short circuit or a short circuit to the ground.
Three, all bright when there is a line or a few lines do not shine
Check the line between 138 and 4953 is not open circuit or Weld, short circuit.
Fourth, the line scan, two lines or a few lines (usually a multiple of 2, regular) with the light
1, check A, B, C, D between the signals is not a short circuit.
2, check the 4953 output is not short with other output.
Five, all bright when there is a single point or more (no law) is not bright
1, find the module corresponding to the control foot measurement is not a short circuit with the Bank.
2, replace the module or a single lamp.
Six, all bright when there is a column or a few columns do not shine
In the LED display module to find the control of the column of the pin, the test is not with the driver IC (74HC595 / TB62726) output connection.
Seven, there are single or single highlight, or the whole line is bright, and not controlled
1, check the column is not short with the power ground.
2, check the line is not short with the power supply positive.
3, replace the driver IC.
Eight, flashing, but the output to the next line of the signal is normal
Check that the corresponding STB latch output is connected to the latch side of the driver IC is not connected or the signal is shorted to other lines.
Nine, flashing disorders, the output is not normal
1, check the clock CLK latch STB signal is not short circuit.
2, check the clock CLK is not the input and output.
3, check the clock signal is not short to other lines.