PCB Tech - How to repair industrial control circuit boards

A circuit board is composed of circuit boards, components, and software. I personally feel that the ability of the maintenance personnel and the inspection and other maintenance tools are very important when repairing the circuit board. It is difficult to repair modern circuit boards if they rely solely on one person's experience and lack the necessary tools. It is also difficult to do so only by advocating testing equipment such as online testers without paying attention to the quality of personnel. When the industrial control circuit board is repaired, the board you face is different and the treatment method is different. But the basic idea is to find out the bad components and replace and repair them. So, can we just replace all the components that can be replaced on the board? I have tried to replace them, but some components need to be debugged, and pay attention to the overall effect. Use online tester and other tools like mine-sweeping, check each component with a mark, and compare the VI curve. In this way, some faults can be found, but it may not be able to repair the board completely, "because the chip passed by the online tester is not necessarily damaged; the chip that passes the test is not necessarily undamaged." And not every component can be in the component library. Found in the machine tool circuit board is constantly updated and upgraded, so your inspection tools must also be constantly updated.

1. The quality of the maintenance personnel directly affects the success or failure of the maintenance. When there is no schematic diagram, a relatively unfamiliar industrial control circuit board needs to be repaired. In addition to a solid foundation in hardware, a maintenance engineer who has a good understanding of the circuit principle and structure is required. When he sees For an unfamiliar circuit board, you should carefully observe the hardware structure to determine the function of the board, and ask the customer what kind of warning signal the board is installed on at the time. When judging the role of a circuit board, it is necessary to construct a block diagram of the secondary circuit board in mind, and analyze which link is faulty from the alarm information.

2. When the industrial control circuit board is repaired, the staff's technique is also very important. Repairing the circuit board is a very delicate work. There are many components and circuit boards and are easily damaged. Therefore, the operation must be very careful and requires the necessary fixtures and other auxiliary tools. You must be proficient in disassembly, welding, etc. Before you start, you must think through the operation process to avoid unnecessary damage. For chips with programs, try to back up those that can be backed up, and don't move those that are not allowed to be backed up. If it is found that the chip with the program is damaged, and no spare or replacement chip is found, the circuit board cannot be repaired.

3. In the process of repairing the PCB circuit board, apart from finding the broken things and fixing them, the most difficult thing is to check whether you have repaired it and debug it on the machine. No matter how you repair it, *you must install it on the machine tool to be able to use it., And the circuit board delivered to the customer must be good, which must be tested on the machine before it is delivered. Our company has purchased a large number of maintenance experimental test benches and simulated production tests based on the customer’s board to ensure delivery The customer's circuit boards can be used normally without delay in production.