1. The port indicator does not light up.
It's the most common failture. Maybe the internal components of the optical transceiver are damaged. You can test whether there is light from the TX end of the module and whether the transmitted light power is within the normal range, or check DDM information by connecting the device. If there is no light output, the transmitted light power or DDM information of optical fiber module are not in the normal range, it is determined the internal components of the optical module are damaged, and contact the manufacturer for repair or replacement.
2. There is light output but no communication
When it happens, the first thing we need to do is to check whether the wiring is connected correctly. Single-mode fibers can only connect to single-mode modules, and multi-mode jumpers can only connect to multi-mode modules. Then check whether the jumpers are loose, which may result in low light reception at one end. Even if there is light coming out, there will be packet loss. If none of the above is a problem, you can try to clean the jumper connector with a dust-free cloth.
3. The module is not compatible
When the module is not compatible, the values are normal, and the port indicator can also flash normally, but transmission cannot be performed. So you should match the optical module of the corresponding brand or write the compatibility code of the brand.
The solutions above can solve most of the simple problems of the optical transceiver. If you encounter a complex problem, it is necessary to ask professional technicians or optical module supplier to solve the problem.