| Power LED | Green | sufficient power to ONT from UPS |
| FLT LED | Off | Normal Operation |
| Red | replace ONT if condition persists after power cycle | |
| PON LED | Green | ONT is communicating with OLT |
| Red | ONT is NOT communicating with OLT | |
| BATT LED | Off | UPS battery monitoring is disabled. |
| Green | UPS monitoring is enabled and battery voltage level is good. | |
| Red | UPS monitoring is enabled and battery voltage level is insufficient. | |
| Laser LED | Off | ONT laser is not transmitting - 1310nm upstream. |
| Green | Laser is active. | |
| Red | Laser has reached end of life. |