Troubleshooting
98
Troubleshooting Using Front Panel LED Indications
The following tables provide troubleshooting procedures based on indications displayed by the
front panel LEDs of a COT line unit, an FPI-729 or FAU-728 List 2 unit, or a COT channel unit.
Line Unit Troubleshooting
Table 29 provides troubleshooting procedures based on indications displayed by the front panel
LEDs of a COT line unit.
Table 29. COT Line Unit Troubleshooting
Indication
Problem
Action
POWER LED off
The COT Shelf is no longer receiving CO
battery.
1
Verify that the fuse on the CO fuse panel is
good.
2
Verify wiring between the COT shelf and
the CO fuse panel, and from the panel to the
CO battery.
The COT line unit fuse F1 has blown.
Replace the fuse.
LOOP 1 (2) SYNC LED
flashing or off
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).
1
Verify the HDSL circuits are terminated
properly and with the correct orientation.
2
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 9 on page 25.
3
Ensure that the HDSL circuit span is within
proper design limits:
•
line loss <35 dB @ 196 kHz
•
pulse attentuation is <28 dB
COLU and RTLU incompatible. That is, one
is a T1 version and the other is an E1 version.
Replace either CO or RT end with the correct E1
or T1 line unit.
LOOP 1 (2) MARGIN
LED on
The HDSL line margin level is below a
preset level.
1
Ensure that the HDSL circuit span is within
proper design limits:
•
line loss <35 dB @ 196 kHz
•
pulse attentuation is <28 dB
2
Verify that the HDSL margin threshold is set
correctly. See “Setting System Parameters”
on page 75.
FAULT LED on
System alarm/fault is detected.
Review Alarm History for trouble source.
Summary of Contents for PG-Flex
Page 10: ...PG Flex System Overview 2 Figure 1 Typical PG Flex Configuration 23 Shelf shown ...
Page 24: ...PG Flex System Overview 16 ...
Page 52: ...Installing PG Flex System Hardware 44 Figure 21 Connecting the Metallic Bypass Pair ...
Page 62: ...Installing PG Flex System Hardware 54 ...
Page 66: ...Terminal Management 58 Figure 28 Connecting an ASCII Terminal to a Line Unit ...
Page 104: ...Performance Monitoring 96 ...
Page 120: ...Troubleshooting 112 ...
Page 158: ...Screen Menus and Definitions A 36 ...
Page 162: ...Acronyms and Glossary Glossary 4 ...
Page 167: ......
Page 168: ......