Fault Isolation
SCP-PLL735-010-03H
60
January 6, 2003
PLL-735 Lists 1, 2 and 3
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 the section “Specifications” on page 2 for the correct values.
DICOLU
AND
RT F
AULT
I
NDICATORS
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 test 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
Color
State
Probable Cause
Solution
PWR
Green
On, all other LEDs
flashing
Application program in PLL-735 has
become corrupt.
Download new software into the PLL-735.
On, all other LEDs
running downward
OK
Wait for software to be downloaded and
PLL-735 has re-started.
On, all other LEDs
running upward
OK
Wait for software to be downloaded and
PLL-735 has re-started.
On FAULT flashing
The PLL-735 detects the RT but the
HDSL loop is drawing too much power
or has a ground fault.
Check the HDSL loop for shorts or
grounds.
On
OK
Flashing
The PLL-735 detects the RT but the
HDSL loop cannot synchronize.
Check the HDSL loop for faults such as
shorts, grounds or bridged taps.
Verify loop length limitations are not
exceeded.
Off
No battery feed to COT shelf.
Verify fuses in equipment bay fuse panel.
Verify CO battery is present on COT shelf
backplane.
SYNC
Green
On
OK
Flashing
The PLL-735 detects the RT but the
HDSL loop cannot synchronize.
Check the HDSL loop for faults such as
shorts, grounds or bridged taps.
Verify loop length and loop loss limitations
are not exceeded.
Off
The PLL-735 does not detect an RT.
Verify an RT is connected to the HDSL
loop.
Check the HDSL loop for faults such as
opens, grounds, load coils or bridged taps.
Verify loop length and loop loss limitations
are not exceeded.
MARGIN Yellow On
The HDSL signal level is too low coming
into the PLL-735.
Check the HDSL loop for faults such as
shorts, grounds or bridged taps.
Verify loop length and loop loss limitations
are not exceeded.
Flashing
The HDSL signal level is too low coming
into the RT.
Check the HDSL loop for faults such as
shorts, grounds or bridged taps.
Verify loop length and loop loss limitations
are not exceeded.
Off
OK
TEST
Yellow On
Wait for subscriber drop test to complete.
