Specifications

24
LOCAL FIBER MUX-6
4.5 Fault Isolation and Troubleshooting
Use Table 4-3 to help you troubleshoot any problems with the Local Fiber
Mux-6.
WARNING
These service instructions are for use by qualified personnel only. To
avoid electric shock, do not perform any servicing other than that
contained in the operating instructions unless you are qualified to do so.
Table 4-3. Fault Isolation and Troubleshooting.
Symptom Action
All front panel indicators are OFF (a) Check that power is supplied to the unit.
(b) Check the fuse inside the AC receptacle
on the rear panel and replace it with a new
one.
(c) Replace unit. The fault is probably in
the unit’s power-supply circuits.
Red LOCAL SYNC LOSS is ON (a) Perform LLB. Yellow TEST indicator
should light and LOCAL SYNC LOSS
should go OFF. If not, replace the local
unit. Otherwise, proceed to step (b).
(b) Perform RLB. Yellow TEST indicator
should light and LOCAL SYNC LOSS
should go OFF. In that case, replace the
remote unit. Otherwise, proceed to step (c).
(c) Perform steps (a) and (b) at the remote
site. If the fault is still not located, replace
both units one at a time. If the problem
remains, the main-channel link is defective
and should be checked.
Red REMOTE SYNC LOSS is ON Perform all the tests as in the case of
LOCAL SYNC LOSS, starting at the remote
site.