Solution of all kinds of broken led screen

Outdoor advertising led screen

Defective pixel is the most common problem of LED screen, which means black points appeared during the working of the led screen. Other problem include whole screen can’t work, parts of led screen is not bright, whole screen crash, parts crash, Totalise etc. now aimed at these problems, simple introduce the solutions:

1.    Output problem

(1)  Check whether the line of the output interface to the signal output IC connection or short circuit

(2)  Check whether Clock latch signal output is normal

(3)  Check whether the last driver IC output data between the mouth is connected to the output interface of data port or short circuit.

(4)  Check whether the output signal is mutually short circuit or short circuit to ground

(5)  Check whether the output flat cable is well

2.    whole screen bright but one line or few line do not bright

Detection the circuit between 138 and 4953, and tell whether it is circuit break, virtual welding or short circuit. 

3.    Whole screen do not bright

(1)  Check whether the power supply and signal lines connect well

(2)  Check whether the test card is identified interface，Red light flashing does not identify test card, check whether the lamp panel is power supply with test card, or light board interface has signal and short circuit identification interface

4. Oblique scan, a regular interlaced not bright, show scenes overlap

(1) Check A, B, C, D, if there is A disconnect between signal input port to 245 or virtual welding, short circuit.

(2) Test 245 corresponding outputs A, B, C, D and whether or virtual welding, open circuits between 138.

(3) Test A, B, C, D between each signal is short circuit or A signal with A short circuit

5．Display disorder, the output signal to the next piece of board is normal

 Test 245 corresponds to the STB latched output connected to the driver IC latch end whether or signal is short circuit to the other line.

6.    whole screen bright, have one row or few rows do not birght

On the module control pin in the column, whether measured and drive IC (74 hc595 are needed/TB62726) output terminal connection.

7.    A single point or single highlighting, or the entire line highlighting, and is not controlled

 (1) Check whether the column with the power to short circuit

 (2) to test whether the line show circuit with positive of the power

 (3) replace the drive IC

8.    display disorder, output unnormal 

(1)    Testing the clock CLK latch STB signal is short circuit

(2)    Testing the clock signal is short circuit to the other line

9.    display lack of color

(1) Check whether the data end of the 245 of the color with input and output

(2) Test the color data signal is short circuit to the other line

(3) Detecting the color of the driver IC level even data between whether there is open circuit or short circuit, virtual welding

10. Screen dithering, have stripes

Check the connection of computer common ground wire is loose, or whether the communication cable is loose. If the operator cannot determine the cause of the problem, or the computer is not very understand, don't open the case, can be dealt with again after contact with the LED display manufacturer.