ADTRAN 1287722G1, Installation And Maintenance Manual

Page: 47 / 56

Troubleshooting
61287722G1-5B 35
Troubleshooting
When troubleshooting a SBU ONT unit, consider the following two principles:
• Because voice and data signals originate at the OLT equipment, a failure of all services
normally indicates the problem is before the SBU ONT. A failure at the OLT equipment
normally results in a loss of service to multiple customers.
• The OLT has diagnostic testing procedures that can monitor the status of every SBU ONT
in the system, which very often can direct you to the root cause of the trouble.
NOTE
The home telephone wires are connected using pivot connectors, and the RJ ‐
11 jack serves as a test access point. In this configuration, inserting a
telephone cable into the RJ ‐ 11 jack will disconnect the SBU ONT from home
wiring and connect the SBU ONT to the inserted cable instead. This allows
the home owner or service provider to diagnose SBU ONT or home wiring
related problems. Inserting an RJ ‐ 11 jack (such as a telephone cable or
telephone test set) into the connector, will connect the telephone set and also
disconnect the subscriber service from the SBU ONT. Hence fault may be
isolated to the SBU ONT or premises wiring.
This section describes how to troubleshoot and correct the following:
• “Faults Indicated with LEDs”
• “SBU ONT Trouble Isolation” on page 36
• “Signal Level Verification” on page 39
• “UPS Communication Signals” on page 41
Faults Indicated with LEDs
Begin troubleshooting at the SBU ONT by checking to see if all LEDs are in their normal state,
shown in Table 9 on page 33. There are separate LEDs for each Ethernet RJ ‐ 45 jack that appear
on the SBU circuit board. If the LEDs are in their normal state, refer to “LEDs in Normal State”
below. If the LEDs are in a fault state, refer to “LEDs in Fault State” on page 36.
LEDs in Normal State
If the LEDs are in the normal state but you are still having problems, complete the following
troubleshooting steps:
1. If the trouble is of a random or intermittent nature, check for loose or broken connections
at the common mounting platform.
2. If the trouble is solid, remove the Customer Provided Equipment (CPE) wiring and
perform the following tests:
• POTS tests described in “Test for POTS Line Faults” on page 34.
• Ethernet tests described in “Provision Ethernet Interface at OLT” on page 34. Verify
the OLT can run and pass the loop ‐ back tests for the Ethernet port.
If the above tests are successful, the indication of the trouble is directed back toward the
CPE wiring/equipment.