Insufficient Power - First, check the powering switch, its power management configuration, and if it's working properly. Also check if there is required amount of power. This document describes how to troubleshoot fiber optic interfaces by addressing some of the fiber optic module and cabling specifications. There are no specific requirements for this document. Check if the fiber optic line has too much loss, exceeding the receiving range of the equipment. S3100 SERIES SWITCHES TROUBLESHOOTING GUIDE. Fiber optic troubleshooting is an essential skill for network administrators, technicians, and engineers responsible for maintaining and repairing fiber optic systems.