During the production and use of SMT, some problems will appear, such as processing errors, improper use, and aging components or even poor use of the product. Total replacement of PCB is not required most of time, maintenance and repairs are necessary under this circumstance. This article displays some skills of circuit board repair.
In general, the maintenance department in our SMT processing plant performs the following operations:
1. Check components
When a product needs to be repaired, it is necessary to check whether the components of each solder joint have errors, leaks, and reversal locations, and the authenticity of the materials have to be considered. If you find that components of each solder joint don’t have errors, leaks, and reversal locations, and materials are authentic, you have to check whether this faulty circuit board is in good condition first, and each component is burned obviously or not and whether the components have been plugged in correctly or not.
2. View the soldering status of the circuit
See whether the circuit board soldering is full, whether there is false soldering, empty soldering, short circuit, and whether the copper skin is obviously warped.
3. Examine the directions of components
Check whether directional components such as diodes and electrolytic capacitors are plugged in the wrong direction.
4. Measure components
Use a multimeter to simply measure the resistance, capacitance, transistor and other components, whether the resistance value becomes larger or smaller, whether the capacitance is open circuit, and whether the inductance is open circuit.
5. Testing
After all the above procedures are performed, the circuit board is powered and tested to inspect whether the board’s functions are normal or not.
6. Repair
If PCB still cannot work after the above procedures are done, it is necessary to look at the schematic diagram of the circuit board to know how it works, and there may be a problem that causes the corresponding function to be unable to be realized.
