Messages and Troubleshooting
8-6 7610-A2-GB20-10
November 1997
Table 8-2. Troubleshooting (2 of 2)
Symptom SolutionsPossible Cause
An LED is not lit. LED is burned out. Run the Lamp test. If the LED in
question does not flash with the
other LEDs, then contact your
service representative.
No power, or the
LEDs are not lit. The power cord is not
securely plugged into the
wall receptacle and into the
rear panel connection.
Check that the power cord is
securely attached at both ends.
The wall receptacle has no
power. Check the wall receptacle power
by plugging in some equipment
that is known to be working.
Check the circuit breaker.
Verify that your site is not on an
energy management program.
Not receiving data;
DSU is not
responding.
DDS line rate/speed has
changed.
Excessive BPVs causing
DSU to become stuck in
Autobaud mode.
Excessive Loop Loss
causing DSU to become
stuck in Autobaud mode.
1. Verify that your subscriber loop is
running at 56 or 64 CC kbps.
2. Verify that the DSU is set to the
same rate as your subscriber
loop. The DSU’s rate is displayed
on the Network Interface Status
screen.
3. If getting Excessive BPVs, verify
that you do not have a bad cable.
If the cable is good, contact the
network provider.
4. If getting excessive Loop Loss
(dB)indications installa higher
4. If getting excessive Loop Loss
(dB) indications, install a higher
quality cable. Refer to Model
7610 DSU LADS Connection
Distances, Table 3, in the
Start-Up Instructions.
5. If the DDS Line Rate (Kbps) field
shows Autobaud, the DSU may
be stuck in Autobaud mode.
Configure Line Rate (Kbps) for
56 or 64 kbps.
6. Run Loopback tests. Refer to the
Tests Available
section of
Chapter 7.
Power-Up Self-Test
fails. Only Alarm
LED is on after
power-up.
The DSU has detected an
internal hardware failure. Reset the DSU and try again.
Contact your service
representative.