Detection methods and necessary maintenance tools for LED display maintenance

Short-circuit detection method, adjust the multimeter to the short-circuit detection block (generally has an alarm function, if it is turned on, it will make a beeping sound), detect whether there is a short-circuit phenomenon, and solve it immediately after the short-circuit phenomenon is found. The short-circuit phenomenon is also the most common LED Display. Module failure.

First, the detection method of LED Display maintenance

1. Short-circuit detection method, adjust the multimeter to the short-circuit detection block (generally has an alarm function, if it is turned on, it will make a beeping sound), detect whether there is a short-circuit phenomenon, and solve it immediately after the short-circuit phenomenon is found. The short-circuit phenomenon is also the most common LED Display module failure. Some can be found by observing IC pins and pin header pins. Short circuit detection should be performed with the circuit de-energized to avoid damage to the multimeter. This method is the most commonly used method, simple and efficient. 90% of the faults can be detected and judged by this method.

2. Resistance detection method, adjust the multimeter to the resistance gear, detect the resistance value of a certain point of a normal circuit board to ground, and then test the same point of another same circuit board to test whether the resistance value is different from the normal resistance value. If not, the scope of the problem is determined.

3. Voltage detection method, adjust the multimeter to the voltage level, detect the ground voltage of a certain point of the circuit suspected of having a problem, and compare whether it is similar to the normal value, which can easily determine the scope of the problem.

4. The voltage drop detection method, adjust the multimeter to the diode voltage drop detection gear, because all ICs are composed of many basic single components, but they are miniaturized, so when there is current passing through one of its pins, There will be a voltage drop across the pin. Generally, the voltage drop on the same pin of the same type of IC is similar. According to the comparison of the voltage drop value on the pin, it must be operated when the circuit is powered off.

Detection methods and necessary maintenance tools for LED display maintenance

2. Essential tools for LED display maintenance

1. 1 electric soldering iron + 1 suction gun each, some solder

2. 1 5V regulated power supply to supply power to the receiving card and the module or unit board to be repaired

3. 1 electric batch for quick disassembly of modules or unit boards

4. Computer + sending card, used to send programs to the receiving card

5. Receiving card + HUB board, used to observe the failure phenomenon of module or unit board

6. One multimeter, used to detect specific faults of modules or unit boards

7. 1 pair of tweezers, scissors and pliers

3. Basic steps of LED display maintenance

1. Determine the type of HUB board used by the module or unit board, so that the interface definition of the cable can be the same

2. According to different types of modules or unit boards, send corresponding programs to the receiving card to ensure that the modules and unit boards are displayed under the correct program, which is the premise to find out the cause of the failure. Generally, the model of the module or unit board will be printed on the PCB board.

3. Observe the module or unit board phenomenon to determine the initial fault. For example, common blind lights, string dots, small squares, etc.

4. Use a multimeter to find out the fault, mainly using the above short-circuit detection method to detect the gap between the chip and the lamp pin.

5. Check again

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