How to Repair Industrial PCB Capacitor Damage
PCB failure caused by capacitor damage, especially the electrolytic capacitor damage, is very common in the electronic equipment, in particular, the most common electrolytic capacitor damage. Capacitor damage can be easily found since the capacitance will become smaller, or completely lost capacity, or leak electricity or short circuit.
The role of capacitors in the circuit is different, the fault occurred also has its own characteristics. In the industrial control printed circuit boards, digital circuits account for the vast majority of capacitors used for power supply filter, while capacitors used as signal coupling and oscillation circuit are less.
If damage occurs in the switching power supply electrolytic capacitor, the switching power supply may not vibrate, and no voltage can be output. Or if the output voltage filtering is not good, the circuit is logic confusion due to voltage instability, the performance of the machine is unstable or the machine is unable to open.
The life of the capacitor is directly related to the ambient temperature, the higher the ambient temperature, the shorter the capacitor life. This law applies not only for electrolytic capacitors, but also for other capacitors. Therefore, when checking fault capacitors, you should focus on heat sources close to the capacitor, such as capacitors next to heat sink next, high-power components, etc., the closer the greater the possibility of damage. Another case of ceramic capacitors appear short circuit, you may find that the capacitor is relatively close to the heating component. Some capacitor leakage is more serious, sometimes your finger may feel hot when touch it, capacitors like this must be replaced.
When troubleshooting, rule out the possibility of poor contact, generally most faults are caused by capacitor damage. Thus, when facing such failures, pay attention to the capacitor, you’ll be surprised by the result after replacing the capacitor.