Early reliability and failure analysis of modern telephone audio systems

Typical early failures of modern telephones, characterized by their inability to provide quality audio performance, were analyzed. Specifics of advanced mass consumer communication electronics reliability and failure analysis have been discussed. Complementary theoretical and experimental methods were applied in order to effectively evaluate diverse acoustical reliability specifics, allocate defects, and reveal their root causes. Practical fault tree for analog and digital technologies has been developed and illustrated; its benefits and limitations are discussed. FA of typical catastrophic and parametric failures of acoustical transducers; special transformers; shifts of parameters and their interaction with software; mechanical assembly tolerance; printed circuits and soldering, etc. are presented. Various fault interactions were found to noticeably contribute to failure aggravation. Recommendations for corrective action were developed.