Revision 01
February 24, 1998
Section 363-712-131-01
PG-Flex FLL-712 List 3A
PairGain Engineering - Plant Series
Page 39
10. Troubleshooting
10.1
Table 9 provides troubleshooting procedures based on indications displayed by the FLL-712 front
panel indicators.
Table 9. FLL-712 COT Line Unit Troubleshooting
Indication
Problem
Action
POWER LED off
1
The COT Shelf is no longer receiving
CO battery.
Verify that the fuse on the CO fuse panel is
good.
Verify wiring between the COT shelf and the
CO fuse panel, and from the panel to the CO
battery.
2
The COT line unit fuse F1 has blown.
Replace the fuse.
LOOP 1 (2) SYNC
LED flashing or off
1
The HDSL line is attempting to
synchronize with the remote terminal
line unit or cannot detect the HDSL
signal from the remote terminal line
unit. This is usually an indication that
there is a problem with the HDSL
circuit between the COT and RT
(assuming the FAULT LED is off).
Verify the HDSL circuits are terminated
properly and with the correct orientation.
Measure the loop resistance of each HDSL
circuit (shorting the pair at the far end). The
loop resistance must be less than that shown in
Table 2.
2
The COLU and RTLU are
incompatible. That is, one is a T1
version and the other is an E1 version
Replace the incompatible line unit
LOOP 1 (2) MARGIN
LED on
The HDSL line margin level is below a
preset level.
Check the preset Margin Alarm level in the
Setup Menu.
FAULT LED on
Faulty FLL-712 COT line unit or faulty
FRL-742 RT line unit
Check that none of the HDSL pairs are shorted
to ground.
Check for continuity from COT to RT on all
HDSL lines.
Replace the COT line unit, if the RT line unit
is confirmed good. Otherwise, replace the RT
line unit.
Summary of Contents for PG-Flex FLL-712
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