The Problem: While not always the transceiver's fault, the optical link loss exceeds the module's budget. Causes include: Dirty or damaged connectors. Damaged, kinked, or bent fiber optic cables (exceeding bend. This paper introduces the common failure causes of abnormal transmit/receive optical power of optical modules and proposes countermeasures to help users quickly locate or solve network failures. SFP Detail Diagnostics Information (internal calibration) Current Alarms Warnings Measurement High Low. The primary causes of optical module failure are performance degradation due to ESD damage, and optical path discontinuity caused by optical port contamination and damage. Modern transmission systems depend on a carefully engineered power budget, and any imbalance introduces operational risk. Unexpected optical levels trigger module alarms such as: If. These compact devices convert electrical signals to optical signals and vice versa, enabling data transmission over fiber optic cables. While generally reliable, failures do occur, leading to frustrating downtime, performance degradation, and costly troubleshooting. Optical port pollution is another major cause of it failure.