Ensure module is fully seated, check optical power levels (Tx & Rx), replace suspect patch cord. Vendor incompatibility, outdated device firmware, incorrect module type for slot. Clean fiber end-faces, reseat module, verify port is enabled, try a known-good module. Thoroughly clean all connections, inspect. The following table lists common abnormal phenomena and solutions during the installation of optical modules: Ⅱ. Key Considerations: Preventing Problems Before They Occur 1. However, locating the fault does not always mean it can be resolved—if the hardware is damaged, the issue can only be fixed by replacing the module. Optical modules are electrostatic-sensitive.