This topic explains the possible causes of optical module faults and provides solutions.


After you insert an optical module into a Smart Access Gateway (SAG) device, the indicator does not turn green.


The optical module is incompatible or damaged.

For more information about the optical module models supported by SAG devices, see Optical module models.
Note Currently, you can only insert optical modules into SAG-1000 devices.


  1. A multi-mode optical module emits visible light. If you can see a red laser on the left of the sending port, the module is working normally. Do not look directly into the sending port.

    A single-mode optical module emits invisible light. You can use a jumper to connect the sending port and the receiving port. If the indicator turns green, the module is working normally.

  2. If the indicator still does not turn green, check whether the optical module is compatible with the device.