Troubleshooting of LED display / LED electronic display / LED large screen
Author:Yang Dong Time:2021-09-12 11:20 Browse(758)
A. The whole board doesn't light up
A. The whole board doesn't light up

Troubleshooting of LED display / LED electronic display / LED large screen

1. Check whether the power supply is connected with the signal line. 2. Check whether the test card is connected with the identification interface. If the red light of the test card flashes, it is not identified. Check whether the lamp board is connected with the test card by the same power supply or ground, or if the signal of the lamp board interface is short circuited to ground, which leads to the unrecognizable interface (intelligent test card). 3. Check whether the 74hc245 is short circuited, Check whether the input and output pins of enable (EN) signal on 245 are faulty or short circuited to other lines
note: mainly check the power supply and enable (EN) signal
B. in oblique scanning, regular interlacing is not bright, and the display screen overlaps
1. Check whether there is broken line or faulty soldering or short circuit between a, B, C and D signal input port and 245. 2. Check a, B, C and D signal corresponding to 245 Check whether there is open circuit or false soldering or short circuit between D output terminal and 138. 3. Check whether there is short circuit between a, B, C and D signals or short circuit between a signal and ground.
note: mainly check the ABCD line signal.

C. one line or several lines are not bright when all light is on.
1. Check whether there is open circuit or false soldering or short circuit between 138 and 4953.

D. two or several lines (usually multiple of 2) when line scanning, Check whether there is short circuit between signals a, B, C and D. check whether the output terminal of 4953 is short circuited with other output terminals.
E. single point or multiple points (irregular) do not light up when it is fully on.
1. Find the control pin corresponding to the module and measure whether it is short circuited with the line. 2. Replace the module or single lamp.
F. one or several columns do not light up when it is fully on.
1 Find the pin that controls the column on the module and test whether it is connected with the output of the driver IC (74HC595 / TB62726,,,)
g. there is a single point or single column highlight,1. Check whether the column is short circuited to the power supply ground.
2. Check whether the row is short circuited to the positive pole of the power supply.
3. Replace the driver IC.
h. display is confused.
but the output signal to the next board is normal.
1 Detect whether the STB latch output corresponding to 245 is connected with the latch end of driver IC or the signal is short circuited to other lines.

I. display confusion.
abnormal output 1. Detect whether the clock CLK latch STB signal is short circuited.
2. Detect whether the clock CLK of 245 has input and output.
3 Detect whether the clock signal is short circuited to other lines.
note: mainly detect clock and latch signal
J. display color missing
1. Detect whether the data terminal of 245 has input and output of this color.
2. Detect whether the data signal of this color is short circuited to other lines.
3. Detect whether there is open circuit or short circuit in the cascade data ports between driver ICs of this color Virtual soldering.
note: the voltage detection method can be used to find out the problem easily.
detect whether the voltage of the data port is different from that of the normal one, and determine the fault area.
K. output problem
1. Detect whether the line from the output interface to the signal output IC is connected or short circuited.
2. Detect whether the clock latch signal of the output port is normal.
3 Check whether the cascade output data port between the last driver IC is connected to the data port of the output interface or short circuited.
4. Check whether the output signals are short circuited to each other or to the ground.
5 Check whether the output cable is in good condition.





the specific problems are solved.
if you have any questions, please check http://www.starshine.icoc.cn/




The above literature is provided by customer service one of starlight LED display maintenance. You can see my space or send me a message,
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