Here are some of the most common hidden causes behind "compatible but not working" situations: • EEPROM coding mismatch • Switch firmware restrictions • DOM/DDM parameter inconsistency • Power budget miscalculation • Temperature instability • Poor interoperability between. Here are some of the most common hidden causes behind "compatible but not working" situations: • EEPROM coding mismatch • Switch firmware restrictions • DOM/DDM parameter inconsistency • Power budget miscalculation • Temperature instability • Poor interoperability between. Based on typical issues encountered with optical modules in daily switch applications, this document summarizes basic troubleshooting steps for resolving common faults: 1. Check compatibility between the optical module and switch Most switch brands have specific compatibility requirements. An optical module is a critical component in modern optical communication systems, directly affecting transmission stability, network reliability, and operational efficiency. However, during installation and daily operation, various issues may arise. If the fault is caused by incorrect configuration or networking environment, change the configuration or networking environment. Check whether the optical modules are Huawei-certified ones.