First, prepare before repair1. First, carefully observe the surface of the fastening force to the surface of the board, there is no obvious fault trace. Such as: an integrated IC or other component with flab-free fracture, whether the circuit board has traces of broken line cracks.
2. Understand the process of failure of the forklift, analyze the causes of faults, and infer the location where the faulty components may exist.
3, understand and analyze the nature of the application of the fault to the open board, and count all kinds of integrated ICs used.
4. The possibility of failure is sorted according to the position of the various integrated IC parts.
5. Use various detection methods, sequentially, and gradually narrow the range of faults in sequence in the order of the possibility.
6. When determining a specific fault device, when replacing the integrated IC, it is best to first install an IC device socket test.
7. If the loading test is still abnormal, it should be detected again until all faults on the fast-moving power supply.
Second, force to the boot door board repair method
1, all kinds of forklifts in the fs-type forklift board, but the unchanged, each forklift board must be composed of various integrated blocks, resistance, capacitance and other devices, so force to the best forklift The turbine is damaged by one or some of the devices, the maintenance of the turbine is based on the above factors. Circuit board maintenance is divided into two parts: the test and maintenance, which detects a very important location. Perform a test of each device on the power-on-board turbine board until the bad piece is replaced, then a circuit board is repaired.
2, the main point of force to the maintenance of the top board is to detect the fault components. The detection is a process of careful finding, determining, and correction of each electronic component failure on the board. In fact, the entire detection process is a test process for the thinking process and provides logical reasoning clues. Therefore, the test engineer must need to turn on various electric forklifts, main control boards, computer boards, panel maintenance, maintenance, testing, and maintenance. I have gradually accumulated experience, and I also rely on past experience. Because a piece of circuit board is composed of thousands of components, when maintenance, maintenance, if the problem is detected by directly testing each component in the board, it will be very expensive. very difficult. Then, from the fault phenomenon to the fault cause, it is an important maintenance means one of the maintenance methods. Because the board installed on the truck, the maintenance is easy to detect its fault point.
3, multimeter test to exceed the board SMT element repair method
Wanli Tests Testing the SMT Components of the SMT Element is very small, very inconvenient with ordinary multimeter pen test, one is easy to cause short circuits, the second is to contact the metal pins of the component pin for the circuit board coated with insulating coatings. part. Here tells you that a simple method will bring a lot of convenience to the test. Take two ports of the slice needle, (depth industrial control repair technology column) will be tightened with the multimeter pen, then take a fine copper wire in a multi-strand cable, tied the black and sewing clothes with fine copper wire Together, welding is soldered again. In this way, if the SMT element is removed, there is no short circuit when it takes the SMT elements, and the needle tip can puncture the insulating coating, straight down the key parts, and no need to fill the gods to scrape the film.
4, force to the maintenance method of the mobile phone short circuit fault "
In the process of power to the boot board door panel repair, if the fault of the public power supply is often large, many devices are shared by the same power, and each device has a short circuit suspicion, if power is optimized There are not many components on the board, and you can find a short road point in the way "big land". If the components are too much, "big" can not be taken by the situation. Here is a comparison method, this method is used, and it is often a short-lived. To have a voltage of a voltage, voltage is 0-30V, current 0-3a, this power is not expensive, about 300 yuan. The open circuit voltage is adjusted to the power supply voltage level, first adjusting the current to the 5V and 0V side of the circuit's power supply voltage point such as a 74-series chip, and slowly increase the current. Hand touch the components of the board, when touching a device, it is often damaged components, and further measurement confirmation can be taken. Of course, the voltage must not exceed the operating voltage of the device and cannot be reversed, otherwise it will burn other good devices. Recommend: LiFePO4 Battery Manufacturer Energy storage battery Manufacturer Integrated machine energy storage battery series Manufacturer Lead lithium battery Manufacturer Outdoor Backup Battery Manufacturer Portable outdoor power supply Manufacturer Power battery Manufacturer Powerwall LiFePO4 Battery Manufacturer Battery rack Manufacturers Telecom LiFePO4 Battery Manufacturer Wall mounted battery storage Manufacturer China Lifepo4 Battery
