How to quickly detect PCB circuit board failure problems

Making a PCB circuit board is not a simple process to complete the board, just drill a hole and then solder the components. The manufacture of PCB boards is not too difficult, and its difficulty depends on the inspection of faults after manufacture. Whether I am a hobbyist or a technical engineer in this field, the PCB circuit board is also a very troublesome problem in the case of adjustment, just like the ape program encounters a bug.

Some people have a passion for tweaking PCB circuit boards. Just as programmers deal with bugs, there are many common PCB problems. In addition to circuit board design, damage to electronic components, short circuit faults, component quality, and PCB circuit board breakage, there are many common problems.

The key to common PCB faults is to concentrate on components, such as capacitors, resistors, inductors, diodes, triodes, field effect transistors, etc., as well as serious damage to integrated integrated circuits and crystal oscillator circuits. A more intuitive way to distinguish the faults of these components can be done by eye investigation. There are obvious burn marks on the surface of electronic components with significant damage. This fault can be dealt with by immediately replacing the difficult part with a new one.

Of course, not all electronic components can be damaged by the human eye, such as resistors, capacitors, diodes, etc. In some cases, no damage can be seen on the outside, and it is necessary to rely on professional special testing tools for repairs. Commonly used detection methods are: digital multimeter, capacitance meter, etc. When detecting an electronic component, if the operating voltage or current is not within the normal range, it indicates that there is a problem with the component or the former component. Replace it now and see if everything is OK.

If parts are damaged, they can be checked with the naked eye or with an instrument. But sometimes when we give the components on the PCB circuit board, we will encounter some undetectable problems, but the circuit board can not work normally. Many beginners have no choice but to make another board or buy one. In fact, in many cases it is the entire process of component installation. Because of the interaction between the various components, the characteristics may not be stable.

In this situation, the equipment is useless for a long time. They were able to try to identify possible faulty areas based on the strength of the current. Skilled engineers with operating experience can quickly identify faulty areas, but the actual damaged parts are not 100% clear. The only way is to try to replace the abnormal parts until the difficult part is found. Last year, when my laptop motherboard leaked, I also had a problem that I couldn't detect when I checked it out for my teacher. Throughout the repair process, I removed and replaced three components, the power system integrated IC, the diodes, and the USB battery charging element (the dark blue jack on the laptop, which charges the machine's battery in standby mode), This is also based on the final analysis. Only when the abnormal integrated circuits are replaced one by one, can it be identified as a short circuit fault of a component next to the south bridge chip.

It is often said that it is actually a problem with electronic components. Of course, if the PCB is the focal point of the components, then there is no doubt about the board's fault. A very simple example is dead tin plating. Due to the processing technology, the problem of disconnection occurs during the entire process of PCB etching. In this situation, if the wire cannot be braided, it can only be processed with thin copper wire flying wire.

The fault of the PCB circuit board is not significantly damaged, and it is indeed very inconvenient to view, but during the entire inventory process, there will be a kind of mental concentration. After finding the problem, there will be an inexplicable sense of satisfaction, and the program processing error is this. In this mood, I often like to check out some boards that can't be repaired, and I think that's a blessing.