The Mysteries of Device Contacts: Why Do They Fail and How to Fix Them

Connections between modules within a device are often not soldered but rather rely on contacts. These contacts might be prone to issues due to various factors, affecting the reliability and longevity of the device. Understanding these issues and how to address them can significantly extend the life of your devices.

Why Do Device Contacts Fail?

In many cases, the surfaces of the contacts may be covered with dirt, grease, or an oxidized layer. These substances significantly increase the resistance between the contacts, leading to poor performance. When you physically shake or hit the device, the contacts may be temporarily cleaned by friction, thus improving the contact's quality for a short time. However, this solution is only temporary, as the issue will likely return.

Designing Reliable Contacts

High-quality electronics often have contacts that are carefully designed to either be gold-plated, which prevents oxidation, or to react with the other contact to form a strong, permanent joint that is immune to humidity and air exposure. Such contacts are typically made for long-term reliability and are not meant to be used repeatedly over time.

Manufacturers and Device Lifetimes

Many manufacturers intentionally design devices to fail within a certain timeframe, typically 2 to 3 years. This strategy is often driven by the need to push consumers towards purchasing new models. However, in most situations, cleaning the contacts with an oxidization remover can significantly extend the device's lifespan, often doubling it. In some cases, cleaning may not be enough if the issue is due to humidity, water, or poor soldering. Such cases may require the replacement of plugs or flexible circuits.

Real-life Examples

One of the author's experiences involved fixing two devices with issues relating to “working for a week after a shake or hit.” The first device was a DSLR camera where the CCD connection flex was oxidized due to thin gold plating. The second was a kitchen hood driver that used to burn a lamp every two weeks and worked for an hour after a shake or hit, which was attributed to bad soldering of an unused socket pad. Resoldering the marked element permanently fixed the problem. It is worth noting that RoHS (Restriction of Hazardous Substances) compliance for electronic devices often uses solder materials that are not as easily workable or as permanent as traditional lead-tin joints. This can increase the likelihood of such issues in RoHS compliant devices.

Conclusion

Understanding the connection between device contacts, the reasons for their failure, and how to fix them can significantly enhance the performance and longevity of your devices. Regular cleaning and careful resoldering, when necessary, can save you from costly replacements and keep your equipment running smoothly.

In conclusion, a thorough understanding and proactive maintenance of your device's contacts can help you make the most of your technology, providing reliable performance over time.