Maintenance
61292006L1-5C
15
MAINTENANCE
The TR OCU DP does not require routine maintenance for normal operation. Do not attempt
repairs in the field. Repair services can be obtained by returning the defective unit to
ADTRAN. For more information, refer to the
section for further infor-
mation.
TROUBLESHOOTING
Follow the steps in
to troubleshoot the installation of the TR OCU DP.
Table 9. Troubleshooting Table
Problem
Possible Solution
No power at the TR DDS-R
• Ensure the TR OCU DP is supplying the necessary voltage to
power the TR DDS-R. Measure tip/ring voltage at the frame (tip
to ground should be –130 VDC or less depending on input
voltmeter impedance; tip to ring should be –125 VDC to –130
VDC; ring to ground should be 0 VDC). The Total Reach DDS
system is not polarity sensitive.
• Measure tip/ring voltage at the TR DDS-R. If voltage is not
present, check the continuity of the cable pair. If voltage is
measured at the TR DDS-R, replace the unit. The TR DDS-R
does not invoke a measurable short between tip/ring, thus
cable resistance measurements must be made with a manually
applied short, and the Total Reach elements removed.
Power, but no synchronization
• Check the cable for load coils.
• Note the signal meter reading on the TR DDS-R during power up
and the synchronization process. Refer to “Signal Loss
Indication” on the applicable TR DDS-R job aid for definitions.
Loop loss can be too great for synchronization to occur.
• Ensure loop length is within allowable deployment guidelines.
• Relocate the TR DDS-R to splice points sequentially closer to the
TR OCU DP to isolate suspect cable sections.
Excessive errors on loop
• Measure the background noise; ensure that it does not exceed
34 dBrn.
• Using a 50 kb filter, ensure that the impulse noise is not greater
than –40 dBm (+50 dBrn).
• Compare resistances of individual conductors. If different, high-
resistance or intermittent opens could be indicated.
Trouble codes
• The TR OCU DP transmits an ASC (9Eh) trouble code toward the
network under the following fault conditions: 2-wire DSL loss of
signal; Loss of synchronization; Open loop.
• The TR DDS-R transmits an ASC (9Eh) trouble code toward the
network from the customer premises for similar 4-wire
customer interface fault conditions.
• ASC (9Eh) is transmitted to the network during loopback
conditions initiated by the TR DDS-R.
