If the indicator light is on at one end but off at the other, swap the fiber jumpers at both ends. However, if one optical module receives signals but the other does not, the problem is likely related to the transmitting optical module or. Check the model of the faulty optical module. When the connection does not work as expected after we set it up according to the Installation Guide, we need to do some troubleshooting. Understand what the indicator light of the fiber media converter means? 1000M-when it is on, it means 1000M speed 100M-when it is on, it represents 100M speed FX/Act-when it is on, it means that the pigtail has been connected, and when it is flashing, it means that data is being transmitted. The function of the fiber media converter is to convert the electrical signal we want to send into an optical signal and send it out. At the same time, it can convert the received optical signal into an electrical signal and input it to our receiving end. Specific troubleshooting methods and solutions for optical modules are as follows: 1.