A, LED display maintenance detection method
1, short-circuit detection, the multimeter transferred to short-circuit detection block (usually with alarm functions, such as General issued the calls of lead) to detect whether the phenomenon of short circuit was found to be immediately resolved after short circuit, short circuit LED display is the most common screen module failure. Others by observing IC pin pin pin and can be found. Short-circuit detection circuit power should be the case in the operation to avoid damage to the multimeter. This method is most commonly used method is simple and efficient. 90% of the fault can be detected by the judge.
2, the resistance detection method, will be transferred to resistance profile multimeter to detect a normal circuit board of a point to ground resistance values, and then test another piece of the same circuit board with a points test and the normal resistance value is different, If the difference is to determine the scope of the problem.
3, the voltage detection method, will be transferred to voltage profile multimeter to detect suspected problems to a point in the circuit ground voltage, compare it with the normal similarity, you can easily determine the scope of the problem.
4, the voltage drop detection, the multimeter test file transferred to the diode voltage drop, because all the IC are composed of integral parts of many units, but small, so when it's in there is a current of a pin when the There will be voltage drop in the pin. Generally the same type of IC similar to the same pin drop, according to the value of comparing the voltage drop on pin good or bad, to be without power in the circuit operation.
1, the electric iron + sniffing each one, a number of solder
2,5 V power supply 1, for receiving cards and maintenance of power supply module or unit board
3, the power granted one, for quick removal module or unit board
4, computer + send cards, send a program used to receiving card
5, the receiving card + HUB board, module or unit board for the observed symptoms
6, a multimeter, for the detection of specific fault module or unit board
7, tweezers, scissors, pliers each one
1, determine the use of modular or unit board HUB board type, so that the interface cable to the same definition of
2, depending on the type of module or unit board, to the receiving card to send the appropriate procedures to ensure that the correct module and cell board under the procedures in the show, which is to identify the cause of the malfunction of the premise. General PCB board will be printed on the module or unit board models.
3, the observation
lcd module tft, or unit board phenomenon, to determine the initial failure. For example, a common blind lights, strings, little boxes and so on.
5, using the multimeter to find fault, mainly using the above short-circuit detection, between the chip and pin to detect light.
6, Maintenance
7, re-testing
