PCBA Tech - PCBA repair method and steps

During the production and use of SMT chip processing, due to problems in the entire PCBA manufacturing processand use, problems such as processing errors, improper use, and component aging will occur. Because many products do not need to be replaced completely. This requires certain repairs and maintenance of the internal circuit board. Then it comes to the repair of the circuit board!

Under normal circumstances, the maintenance technology of the processing plant will perform the following operations.

1. Check the components
When the product needs to be repaired in the SMT chip processing plant, it is first necessary to determine whether there are errors, leaks, and inversions in the components of each solder joint. Confirming the authenticity of no materials is also a situation that needs to be considered. Not all are better than North China. If errors, leakage, upside-down, and authenticity are eliminated, a faulty circuit board can be obtained. First, check whether the circuit board is intact, whether the components are obviously burned out and inserted correctly.
2. Welding status analysis
The defects of the circuit board are basically 80% of the defects of the solder joints. Whether the solder joints are comprehensive and abnormal, first of all, please refer to ISO9001 quality system management standards, and various SMT processing welding quality standards to check whether there are defective welding, false welding, short circuit, whether the copper skin is obviously improved, and other visible to the naked eye defect. If so, you need to repair the defect of this product, if not, you can proceed to the next step!
3. Component orientation detection
In this session, we basically eliminated some visual defects. Now we must carefully check diodes, electrolytic capacitors, etc. For the most-used components on the circuit board, there are other prescribed directions, or is the negative electrode of the component required for the positive electrode inserted in the wrong direction?
4. Parts tool inspection
5. If all the naked eyes judge that there is no problem, we need to borrow some auxiliary tools at this time. The most commonly used SMT chip processing factories a multimeter to directly measure resistance, capacitance, transistors, and other components. The most important thing to check with a multimeter is to check whether the resistance value of these components does not meet the normal value and becomes larger or smaller. Whether the capacitor is open, whether the inductance is open, etc.
6. Power on test
After the above process is completed, the conventional problems of the parts are basically eliminated. After the power is turned on, the circuit board will not be damaged by ablation due to a short circuits or bridging. Turn on the power and check whether the corresponding function of the circuit board is normal