LED display if there is a problem how to detect and repair?
Below as an introduction to using a multimeter four methods to detect cell board faults have solutions, LED display maintenance detection method of 1, short circuit test, the multimeter to the short circuit test block (
Generally has alarm function, such as the general principles of the guide issued songs)
, detect whether there is a short circuit phenomenon, found that should be resolved immediately after the short circuit, short circuit fault phenomenon is the most common type of LED display module.
By observing the IC pins and needle pin can be found.
Short circuit test should be under the condition of the power circuit operation, avoid damage to the multimeter.
This method is the most commonly used to the method of simple and efficient.
90% of the failures can be test judgment through this method.
2, resistance test, the multimeter to the resistance, the detection of a normal circuit board points to the ground resistance, detection of another piece of the same circuit board of the same point test, if there are different with normal resistance if different criterion to determine the scope of the problem.
3, voltage test, dispatch multimeter to voltage, detecting circuit in question at some point to ground voltage, compare whether similar to normal, can easily determine the scope of the problem.
4, pressure drop test, will be transferred to the pressure drop of the diode detecting multimeter, because all the IC is composed of the basic unit of many pieces, only the miniaturization and so on one pin when it is energized, will exist voltage drop on the pin.
Generally the same type of IC pins on the pressure drop, according to the pressure drop on the pin value is good or bad, must be under the condition of the power circuit operation.
1 second, LED display and maintenance necessary tools, soldering iron + 1 a smoking gun, solder number 2, 1, 5 v regulated power supply to the receiving card, and maintenance of power supply module or unit board 3, electric group 1, is used to quickly remove the module or unit board 4, computer + send CARDS, to send program to receive card 5, receive card + HUB board, used to observe module or unit 6, multimeter, a fault phenomenon, module or unit plate used in the detection of specific fault 7, tweezers, scissors, cutting pliers 1 to 3, LED display maintenance basic step 1, determine the module or unit board using the HUB board type, in this way can row line interface definitions.
2, according to the different types of modules, or unit board, to the receiving card sends the appropriate procedures, to ensure that the module and unit plate under the correct procedures, according to the premise of this is to find the cause of the problem.
Generally with the module or unit on the PCB board.
3, observation module or unit board, determine the initial failure.
Small cross points, such as common blind lamp, square, etc.
4, using a multimeter to find fault, mainly is to use the short circuit test, to test the chip and lamp feet between.
5, and test again.