Fault Isolation
950-779-115-02, Revision 02
12
March 17, 2000
PRL-770 and PRL-779 List 1E and 2E
T
URN
UP
AND
T
ESTING
To continue the installation of your PRL-770 and PRL-779 for readiness:
1
Ensure that at least one COLU is installed into the PG-Flex
Plus
COT shelf. Refer to the appropriate COLU
Technical Practice for verifying the COLU installation.
2
Locate the HDSL Tip and Ring on the protector block or punchdown, apply a short between the HDSL Tip
and Ring conductors for at least 3 seconds. Start-up begins in 3 seconds after removal of the short. Within 2
minutes the system should provide dial tone and battery voltage on the subscriber pairs.
3
Listen for a dial tone using the customer phone line.
4
If dial tone is not heard, then refer to the appropriate COLU Technical Practice for COLU Fault Indicators.
F
AULT
I
SOLATION
The following sections detail the fault isolation procedures. For sections that indicate a condition such as distance
limitation exceeded, refer to
for the correct values.
COLU F
AULT
I
NDICATORS
At the CO, you can use the VT-100 terminal to initiate a subscriber drop test to determine the cause of any of the
following problems.
provides procedures for isolating faults indicated by the COLU LEDs.
Table 1.
COLU LED Fault Isolating
LED
Mode
Condition
Procedure
None
On
processor in the COLU stopped
1
Remove and re-insert the COLU.
2
At the VT-100 interface, go to the COLU Main screen to view the
Performance report to verify that no alarms exist. If the COLU Main screen
cannot be viewed, a communication error exists, indicating a faulty COLU.
3
If the LEDs do not illuminate, replace the COLU.
Fault
On
indicates an existing alarm
condition on the COLU
1
At the VT-100 interface, go to the COLU Main screen to view the
Performance report to determine the cause of the alarm. Correct the
condition, if possible. If the COLU Main screen cannot be viewed, a
communication error exists.
2
Remove and re-insert the COLU.
3
If the communication error still exists, replace the COLU.
M
argin
On
•
distance limitation exceeded
1
At the VT-100 interface, go to the COLU Main screen to view the
Performance report to verify that no alarms exist.
•
fault in HDSL line
2
Initial installation, check engineering records for distance between COT
shelf and RT.
•
faulty COLU
3
If existing installation, measure loss of HDSL line to ensure that the
maximum attenuation value has not been exceeded.
4
Replace the COLU or the RT.