Outdoor LED display old problems?
The check module power board!
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LED display - knowledge
LED display often appear all sorts of problems in the use, today, we summed up the 'LED display outdoor module power supply board breakdown maintenance solution', to share with everyone here.
The whole plate is not bright one, check whether the power supply and signal wire connection.
2, check whether the test card is to identify the interface, the 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.
3, testing 74 hc245 presence of virtual short circuit welding, corresponding enabled (on 245
Signal input and output whether foot virtual welding or short circuit to the other line.
Note: check the power supply and can make (
In oblique scan, A regularity of interlaced not bright display picture overlapping 1, check A, B, C, D if there is A disconnect between signal input port to 245 or virtual welding, short circuit.
2, testing 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.
Note: the main detecting ABCD line signal.
On a line or lines at dawn, detection 1 between 138 and 4953 lines or virtual welding, open circuits.
In the line scan, the two lines or a few lines (
Generally is a multiple of 2, regular)
Light at the same time, detection 1 A, B, C, D whether short circuit between the signal.
2, test whether 4953 output with other output short circuit.
All bright there is a single point or multi-point (
Don't light 1, find the corresponding control module whether foot measurement with our short circuit.
2, module or single lamp replacement.
On 1, there is one or a few columns dawn on the module control pin in the column, whether measurement and drive IC (
Output terminal connection.
Have a single point or single highlighting, or the entire line highlighting, and is not controlled, check whether the column 1 short circuit and power supply.
2, check whether the bank the positive short circuit and power supply.
3, replace the driver IC.
Showed that chaos, but normal output signals to the next board 1, 245 corresponding STB latched output end connected to the driver IC latch end whether or signal is short circuit to the other line.
According to chaos, the output is not normal 1, testing the clock CLK latch STB signal is short circuit.
2, test of 245 clock CLK input and output.
3, testing the clock signal is short circuit to the other line.
Note: the main testing the clock with the latch signal.
Showed a lack of color, 245 of the color of the data input and output.
2, test the color data signal is short circuit to the other line.
3, test the color of the driver IC level even data between whether there is open circuit or short circuit, virtual welding.
Note: the available voltage test is easy to find the problem, detecting data voltage is different from normal whether mouth, determine the fault zone.
There is something wrong with the output 1, check whether the line of the output interface to the signal output IC connection or short circuit.
2, test the output clock latch signal is normal.
3, test the last driver IC level between the output data is connected to the output interface of data mouth mouth or short circuit.
If there is a mutual 4, output signal of short circuit or short circuit to ground.
5, check the output lines are in good condition.