How to Troubleshoot Common Faults of Telephone Optical Terminal?

Device cannot be powered on

1. Check whether the power cable is connected correctly.
2. Check whether the voltage is within the allowable operating range of the device.
3. Check whether the power is within the operating range.
   2M link failure
4. First, check whether the interface impedance matches. Ensure that the impedance of the connected device is consistent with that of the device itself.
5. Each E1 channel has an indicator light. A lit indicator means the corresponding E1 signal is lost; under normal operation, it should be off. If the indicator is lit, check whether the 2M cable and BNC connector of the device's E1 port are in good contact.
6. Next, check whether the device itself can operate normally. The test method is to use a 2M cable to loop the transmit and receive ports of one device (i.e., E1 loopback). If the LOS red indicator goes off, the E1 port of the device is normal. Both ends should be checked in this way.
   Note: The loopback test can only be performed when the device clock mode is set to master clock.
   Optical loss alarm
   When the optical alarm indicator (NOPO) is lit, it means the optical fiber connection has not been established.

1. Physical condition of the optical fiber:

1. First, check whether the optical fiber is in good contact with the device. Re-plug the fiber connectors at both ends into the optical ports of the devices to ensure good contact.
2. Check whether the optical fiber is intact.

2. Device self-test: Next, check whether the device itself can operate normally. The test method is to use one optical fiber to connect the transmit port and receive port of one device (i.e., optical loopback). If the red indicator goes off, the optical port of the device is normal.
3. When the optical fiber is single-fiber:

1. Check whether the optical modules are correct: generally, one end uses a 1310nm optical module and the other end uses a 1550nm optical module.
2. Check whether the fiber distance meets the requirements, such as 20Km, 40Km, 60Km, etc.
   High bit error rate on E1 port
3. Check whether the interface impedance is correct.
4. Check whether the grounding is correct.
   Service failure
   Telephone service failure
5. Physical connection correctness: Check whether the telephone output interface corresponds to the service interface, whether the output telephone interface is reliable, and whether the RJ45 connector is crimped correctly and properly.
6. Device settings: Confirm whether the DIP switches on the panel for the CO (central office) end and the remote end are set correctly.
7. Confirm whether the device is operating normally.
   Ethernet failure
8. First, check whether the network cable connection method is correct.
9. Check whether the RJ45 crimping meets the Ethernet cable crimping requirements.
10. Check whether the configurations of the PCs on both sides are correct, whether they are on the same subnet, and whether the IP addresses, workgroup, gateway, etc. on both ends are correctly configured.