Chapter 5 chapter 5troubleshooting, Chapter 5 troubleshooting -1, Chapter 5 troubleshooting – CANOGA PERKINS 2370 High-Speed Universal Fiber Optic Modem User Manual

Page 49

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EdgeAccess® Universal Chassis System

Chapter 5
Troubleshooting

Use the diagnostic procedures in this section to test and troubleshoot the 2370. Before starting the
diagnostics, obtain this equipment:
 Multimeter
 Fiber Optic Power Meter
 Short (1 m or less) fiber optic jumper cable
 Bit Error Rate Tester (BERT)

Table 21 lists troubleshooting strategies for various symptoms.

Table 21. Symptoms With Possible Causes and Actions

Symptom Possible

cause(s) Corrective

action

No power indicator on front
panel(s)

No AC power

Check AC power source

Defective modem

Replace modem

Local or Remote sync error Faulty modem, cable or connector. If

the modems are configured in a tail
circuit (one is externally locked and
the other is slave), verify that the
externally locked modem has a clock
on its TT (or equivalent) leads that
matches its rate switch.

Run Loopback and BERT
tests

Cable loss exceeds modem
loss budget

Faulty fiber optic cable

Replace defective cable

Faulty fiber optic connector

Polish or replace connector

Loopback test passes, but
modems will not pass data

Modem not configured properly

Check and correct switch
and jumper settings on all
devices

Interface cables damaged or wired
incorrectly

Repair or replace cables

Modem fails BERT test
when optically looped back
to itself

Faulty modem or electrical interface Replace faulty modem

Modem fails BERT when
looped locally

Faulty modem or electrical interface Replace faulty modem

Model 2370 User Manual

5-1

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