Cisco GainMaker Optoelectronic Node 1GHz with 65 86 MHz Split Installation Guide
Chapter 4 Troubleshooting
Troubleshooting Carrier-to-Noise Problems
Complete the following steps to troubleshoot carrier-to-noise problems.
Possible cause
Solution
Low optical input to the node. The
optical input level should be
typically 0 dBm. Refer to the system
design print for the proper level.
If connectors are dirty, clean them. Refer to
Cleaning Optical Connectors (on page 99).
Inspect fiber routing and management tray for
fibers that might be wrapped too tightly.
Check for proper optical output from
transmitter.
Check the link loss.
Replace any scratched connectors.
Low RF input at transmitter.
Verify RF input to the transmitter.
Check all amplifiers preceding the transmitter
for proper inputs and outputs.
Failure in optical receiver.
Replace the receiver module. Use the output
test point of the optical receiver to verify
output levels.
Broken SMB jumper from node
optical motherboard to the RF
amplifier.
Replace the jumper between the optical
motherboard and the RF amplifier forward
input.
Note: An authorized repair center must
Note: An authorized repair center must
perform this procedure.
Defective or improperly spliced
optical coupler between headend
transmitter and node.
Replace or re-splice the coupler.
Make sure all unused fiber pigtails are
terminated.
Unterminated leg of optical coupler.
Make sure all unused fiber pigtails are
terminated.
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