ADTRAN 1200270L1, Manual

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Chapter 11. Testing and Troubleshooting
61200270L1-20 DSU III ARdc User Manual 11-5
TROUBLESHOOTING
This section provides a quick and easy means of diagnosing suspected
problems associated with local or remotely attached ADTRAN DSU/
CSUs. Two separate troubleshooting sections are provided; one focuses
on new installs, the other on existing circuits.
Messages from the DSU/CSU
The DSU III ARdc displays messages on the LCD display and LEDs con-
cerning the status of the unit and the local loop. If the Alarm LED is on,
one or more of the messages shown in Table 11-1 are displayed on the
LCD.
Table 11-1. Messages from the DSU/CSU
The S
TATUS
menu must be selected in order for the unit to
display status messages. Pressing
Quick
returns to the M
AIN
menu, where S
TATUS
can be selected.
Message Meaning Probable Cause Action
LOOP IS
NORMAL
Good local loop
signal being
received from the
telco. Indicates good
local loop. No action required; unit
properly connected to
telco circuit.
OPEN LOOP Unit not receiving
a signal from the
telco.
Bad telco cable
from the DSU to
telco jack or bad
circuit to telco. Replace telco cable
from DSU to wall jack. If
a problem persists,
contact telco provider.
NO RX
SIGNAL
Unit detects
sealing current
but no data signal
from telco. Bad conductor in
telco cable from
DSU to telco jack
or bad circuit to
telco. Replace telco cable
from DSU to wall jack. If
a problem persists,
contact telco provider.