How to Repair LED Display Simply by Yourself?

Full color led display screens are commonly used in outdoor screens. Many activities use display screens, such as dinners party, wedding banquets, stage programs, plazas, etc. As the led display screen is the most important modern display device, we made a simple maintenance analysis as the following several points.

The repair tools needed are: multimeter, electric iron, blade, tweezers.

Judging the problem must be handled from the most important to least important, and from the obvious and serious problems to small ones, such as short circuit should be high priority to deal with.

1. Observation method: directly observing with the eyes, sometimes the circuit can be seen by the eyes, such as the PCB line due to scratching, making it disconnection, sometimes accidentally broken by electric drill.

2. Contrast method: Contrast method is very important and critical. Sometimes we can't see by our eyes whether the IC burns out or not. We can replace it with good IC. Sometimes we can't remember if the signal is connection. We can use good LED module to measure the voltage or current at the corresponding position for comparison.

3. Exclusion method: Sometimes there are many reasons for a fault. We can deal with it one by one. If you don't remember, you can look at the handling of the common faults in the front, and eliminate them one by one!

4. Resistance detection method:adjust the multimeter to the resistance file,detect the grounding resistance value of a point on a normal LED module circuit board, and then test the same point of another identical circuit board to test whether the normal resistance value has different.if different,the scope of the problem can be determined .

5. Voltage detection method: Adjust the multimeter to the voltage file to detect the voltage to the ground at a certain point of the circuit suspected of having a problem, and compare whether it is similar to the normal value. Otherwise, the range of the problem is determined.

6. Short-circuit detection method: adjust the multimeter to the short-circuit detection block (some are diode voltage drop or resistance file, generally have alarm function), detect whether there is a short circuit phenomenon, and find that the short circuit should be solved firstly, so that it does not burn other devices.  This method must be operated in the situation of a power be put-off to avoid damaging the multimeter.

7. Voltage drop detection method: adjust the multimeter to the diode voltage drop detection file, because all ICs are composed of a basic number of unit parts, but they are miniaturized, so when there is current on one of its pins, so there is the voltage drop cross the pin.Generally, the voltage drop on the same pin of the IC of the same model is similar. we can compare it is good or bad according to the voltage drop value on the pin, but the circuit must be powered off. This method has certain limitations.For example,if the device under test is high-resistance, it will not be detected.

Maybe the method is much more than that, but we are also familiar with these methods!

Repairing other can be summarized into three points.

1. Short circuit

Many faults are caused by short circuits.We just need to dispose of the short circuit.

2. Open circuit

As the name implies, the signal is interrupted.We only need to connect the signal interrupted line.

3. IC damage

The IC damage can be judged by the above method, then replace it if judging it is bad.