Outdoor LED display problems ? Time to check the LED modules circle board
The module is not bright at all
1. Check whether the power supply and signal cable is connected.
2. Check that the test card has identified the interface or not. Red flashing means not identified , Check whether the LED module is in the same power as the test card OR A short circuit in the LED module’s interface caused the interface to be unrecognizable.
3. Detect 74HC245 whether there is a short circuit , Corresponding EN signal on the 245 Whether the input and output pins are soldered or short-circuited to other lines . Remarks : Mainly check the power supply and signal.
Regular interlaced display overlaps during point sweep
1. Check whether the A · B · C · D signal input port is connected to 2 · 4 · 5 to see if there is any broken wire or short circuit.
2. Detects whether the ABCD output terminal of 2.4.5 corresponds to 1.3.8 or not.
3. Detects short circuit between A·B·C·D signals or short circuit to ground . Remarks : Mainly detects A·B·C·D line signals.
One or several lines are off when all lights are on
1. Check if the line between 138 and 4953 is open or short circuited.
In line scanning, two or more lines (usually a multiple of 2 and it is regular) light at the same time
1. Detects short circuit between ABCD signals.
2. Detects whether the 4 9 5 3 output is shorted to other outputs.
There is a single or multiple points (irregular) when the light is bright
1. Find out if the corresponding control pin of this LED module measures short circuit with this one.
2. Replace the LED module or single lamp.
One or more columns are not bright when fully bright
1. Check if the column is short circuited with the power supply.
2. Check if the line is shorted to the positive side of the power supply.
3. Replace its driver IC.
The display is confusing, but the signal output to the next board is normal
1. Detects whether the corresponding STB latch output of the 245 is connected to the latch of the driver IC or the signal is shorted to other lines.
The display is confusing and the output is abnormal
1. Detection clock CLK latch STB signal is short or not.
2. Detect 245 clock CLK input and output.
3. Detects whether the clock signal is shorted to other lines.
Remarks : Main detection clock and latch signal.
Show lack of color
1. Detect whether the data of the color of 245 has input and output.
2. Detect whether the color data signal is shorted to other lines.
3. Check whether the cascaded data port between the driver ICs of this color has an open circuit or a short circuit.
Remarks：The voltage detection method can be used to find the problem more easily. The voltage of the test data port is different from the normal one. The fault area is determined.
There is a problem with the output
1. Detect whether the output interface to the signal output IC’s line is connected or short-circuited.
2. Check the output port clock latch signal is normal.
3. Detect whether the cascade output data port between the last driver IC is connected to the data interface of the output interface or is short-circuited.
4. Whether the output signals are short-circuited or shorted to ground.
5. Check the output cable is good.