Failures of electronic components can be roughly divided into two categories: electrical parameter damage and physical damage. Damage to electrical parameters is mainly due to the voltage or current the component withstands exceeding its rated value, causing it to fail to work properly. Physical damage involves physical damage to components, such as breakage, deformation, or abnormal changes in resistance parameters. These damages not only reduce the service life of the equipment, but also increase repair costs. Therefore, understanding the specific manifestations of these damages is crucial to developing effective preventive measures.
Detailed observation of resistor damage
Resistors, as one of the most numerous components in electronic circuits, their stability is crucial to the normal operation of the entire circuit. However, resistor damage does not always occur frequently, and the damage pattern is somewhat predictable. For example, open circuit failure of a resistor is the most common problem, followed by an increase or decrease in resistance. It is worth noting that low resistance values (below 100Ω) and high resistance values (above 100kΩ) are more susceptible to damage, while resistance values in the middle range are relatively stable. In addition, damaged resistors usually have some appearance changes, such as burnt or blackened, which provide intuitive clues for fault diagnosis.
Among the different types of resistors, carbon film resistors and metal film resistors have become the focus of attention due to their wide range of applications. The damage characteristics of these two types of resistors are: low-resistance resistors are often easy to detect when damaged because they tend to be burned and blackened; while high-resistance resistors are difficult to judge by appearance even if they are damaged. For wirewound resistors, especially when used in large current limiting applications, damage is often accompanied by blackening, cracking or cracks on the surface. The damage to cement resistors and fuse resistors may not leave obvious appearance traces, which requires technicians to be more meticulous and comprehensive during inspection.