LED display panel board failure and treatment

LED display panel board failure and treatment
A. The entire board is not lit
1, check the power supply and signal cable is connected.
2, to check whether the test card to identify the interface, the test card red lights flashing is not recognized, check the light board with a test card with the power to, or light board interface signal shorted to ground leading to the interface does not recognize. (Intelligent test card)
3, testing the 74HC245 whether Weld short circuit, corresponding to the enable (EN) signal input and output pin 245 on the Weld or short circuit to the other line.
Note: Check the power and enable (EN) signal.
B. Point oblique scan, regular interlaced bright display overlap
1, check the A, B, C, D, signal 245 between the input exported broken or cold solder joint, short-circuit.
2, the detection of 245 corresponds to the A, B, C, D output and 138 is open circuit or cold solder joint, a short circuit.
3, the detection of A, B, C and D signals whether short-circuit or a signal to short-circuit.
Note: The detection ABCD line signal.
C. Full brightness when the line or lines does not shine
1, the line between the detection of 138-4953 is open circuit or cold solder joint, a short circuit.
D. Line scan, the two lines or a few lines (usually a multiple of 2, regular) light at the same time
1, test A, B, C, D signal short circuit.
2 detected 4953 output with other output short circuit.
E. Single point or multipoint (irregular) does not shine full bright
1, find the module corresponding to the control pins to measure whether short-circuit and the Bank.
2, the replacement module or single lamp.
F. When all light does not shine one or several columns
Control pin of the column found in the module, measuring whether the driver IC (74HC595/TB62726,,,) connected to the output.
G. Single point or a single highlight, or highlight the entire line, and not controlled
1, check whether the column is with the power to short circuit.
2, detection of the line short-circuit with the positive power supply.
3, the replacement of the driver IC.
H. Show confusion, but the output to the normal signal of under one board
1, the detection of 245 corresponds to the STB latch output driver IC latch side is connected or the signal is shorted to the other line.
I. Show confusion, the output is not normal
1, the detection of the clock CLK latch STB signal whether a short circuit.
2, the detection of 245 clock CLK input and output.
3 to detect the clock signal is shorted to the other line.
Note: The detection of clock and latch signals.
J. Lack of color.
1, the data side of the detection of 245 color input and output.
2, detection of the color data signal is shorted to the other line.
Between the level 3, testing the color of the driver IC with data port open or short circuit, Weld.
Note: You can use the voltage detection method easier to find the problem, the mouth of the test data voltage and the normal is different from the fault zone.
K. Output
A detection output interface to the signal output IC line is connected or short circuit.
2, the detection output clock latch signal is normal.
Between the level 3, the detection of the last one driver IC output data port whether the output interface data port connection or whether a short circuit.
4, the output signal each other short-circuit or shorted to ground.
5, check the output cable is good.