Fault Isolation; Colu And Rt Fault Indicators - ADC PG-PLUS PLL-720 Technical Practice

SCP-PLL720-020-03H
F I
AULT SOLATION
COLU RT F
AND
At the CO, you can use the Craft interface to initiate a SDT to determine the cause of any of the following
problems. The SDT performs Hazardous Potential, Foreign Voltage, Resistive Faults, Receiver Off-Hook, and
Ringers Tests. At the customer site, the following sections provide procedures for isolating faults indicated by the
COLU LEDs.
LED Mode Condition
None On processor in the COLU stopped 1 Remove and re-insert the COLU.
Fault On indicates an existing alarm
condition on the COLU
M On distance limitation exceeded
argi
n
fault in HDSL line
faulty COLU
M Flashing distance limitation exceeded
argi
n
fault in HDSL line
faulty RT
SYNC Off HDSL line has lost
synchronization
distance limitation may have
been exceeded
COLU is faulty
PWR Off no input power
on-board fuse is blown on
COLU
PWR Flashing HDSL line open
an overload exists
PLL-720, PLL-721 List 2's
I
AULT NDICATORS
Procedure
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.
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.
1 At the VT-100 interface, go to the COLU Main screen to view the
Performance report to verify that no alarms exist.
2 Initial installation, check engineering records for distance between COTS
and RT.
3 If existing installation, measure loss of HDSL line to ensure that the
maximum attenuation value has not been exceeded.
4 Replace COLU or the RT or both.
1 Initial installation, check engineering records for distance between COTS
and RT.
2 If existing installation, measure loss of HDSL line to ensure that the
maximum attenuation value has not been exceeded.
3 Replace the COLU or the RT or both.
1 Initial installation, check engineering records for distance between COTS
and RT.
2 If existing installation, measure loss of HDSL line to ensure that the
maximum attenuation value has not been exceeded.
3 Replace the COLU or the RT or both.
1 Ground fault condition exists.
2 Check input power at COTS backplane with COLU removed.
3 If power is present at COTS backplane, replace the COLU.
1 Check line continuity and resistance.
2 COLU power supply or RT may be faulty.
January 6, 2003

COLU and RT Fault Indicators

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