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Experience Sharing of An Engineer on PCB Troubleshooting

John is a PCB engineer. He said, “It’s not easy to make PCBs according to the process. Just drill a hole to make components. It’s not difficult to make PCBs. What’s difficult is to check the faults after the PCBs are made. “

Whether it’s a personal enthusiast or an industry engineer, it’s a headache to encounter problems when debugging PCB, just like programmers encounter bugs.

Some people have a strong interest in debugging PCB, just as programmers are solving bugs. There are many common PCB problems.

What Are The Common Circuit Board Problems?

Common problems includes circuit board design, electronic components damage, short circuit, the quality of components, PCB circuit board broken line fault, etc.,

Circuit Board Design

Refer to the PCB design, there are some many problem can be occured. You can check some books to reference or ask the others for help.

Damage of Electronic Components

Common PCB circuit board fault is mainly concentrated in the components above. Such as capacitors, resistors, inductors, diodes, triodes, FET, etc.

damaged component on pcb
How to Check The Damage of Electronic Components?
  • Observe through the eyes
    The more intuitive way to judge the faults of these components can be observed by eyes. There are obvious burning marks on the surface of obviously damaged electronic components. Like this kind of fault, the problem can be solved by replacing the component with a new one.
  • Usually Check Tools (Multimeter, Capacitance meter, etc.) for Professional Inspection
    Of course, not all electronic components damage can be observed with the naked eye, such as the resistance, capacitance, diodes and triodes mentioned above. In some cases, the damage can not be seen from the surface, so professional inspection is needed.

For maintenance, the commonly used inspection tools include: multimeter, capacitance meter, etc. If the voltage or current of an electronic component is detected to be not within the normal range, it indicates that the component has a problem. Replace it directly and check again to see if it is normal.

Quality of Components

If the components are broken, they can be detected either by eye observation or by instrument detection. However, sometimes when we put the components on the PCB board, we will encounter the situation that the circuit board can’t work normally but we can’t detect them. Many novices have no choice but to make a new board or buy one. In fact, in this case, it is often during the installation of components that the performance may be unstable due to the coordination of various components.

In this case, the instrument has been unable to help, you can try to judge the possible range of fault according to the current and voltage. Try to narrow it as far as possible. Experienced engineers may be able to quickly judge the fault area, but the specific components which is broken can not be 100% determined. The only way is to try to replace the suspicious component until the problem component is found.

John said, ” My laptop motherboard was flooded last year. When I was repairing it for the master, I also encountered the problem that I couldn’t detect the fault. During the maintenance process, I replaced the components three times, including the power supply chip, diode and USB charging element ( the blue socket of the notebook, which can charge the device when it is turned off). Finally I replaced the suspicious chip through wave after wave of detection and troubleshooting. It was finally determined that a component on the side of the south bridge chip was short circuited. “

Broken Line Fault of PCB

All of the above are actually problems of electronic components. Since PCB is the foothold of components, circuit board faults certainly exist. The simplest example is the dead tinning part. Due to the manufacturing process, in the process of PCB corrosion, there may be a broken line problem. In this case, if it is impossible to make up the wire, then it can only be solved by using thin copper wire flying wire.

What’s Your Feeling?

“PCB circuit board fault is not obviously damaged, it is very troublesome to check. In the process of checking, there will be a spirit of concentration. After finding out the problem, there will be inexplicable sense of achievement. This is the mood for programmers to solve bugs. I often like to check some boards that are difficult to repair. I think it’s a kind of fun.” John said with pride.