Lucent Technologies DDM-2000 OC-3, User & Service Manual

Page: 2010 / 2536

363-206-285 Trouble Clearing:
TAP-112
Issue 2, February 2000 Page 12 of 16
DDM-2000 OC-3 M
ULTIPLEXER
29. !
CAUTION:
Removal of an unprotected circuit pack may cause service interruption.
NOTE:
The –48V power feeders/fuses on the User Panel supply power to
DC-to-DC converters on the TGS, TG3, OLIU, MXRVO, DS3, TMUX, and
SYSCTL circuit packs. It is unlikely that a circuit pack failure would cause
only one feeder fuse to blow. The more probable cause of failure of only
one feeder fuse would be a short of the backplane feeder path or a
problem with a circuit pack shelf connector. After a thorough inspection of
the backplane, if no trouble is found, the circuit packs can be removed
one at a time to try and isolate the trouble.
Remove
one of each pair of circuit packs listed in the above note and replace
blown –48V fuse. If fuse does not blow again, reinstall all removed circuit
packs one at a time, beginning with the SYSCTL. Replace any circuit pack that
causes the fuse to blow (DLP-523). If fuse blows again with one of each pair of
circuit packs removed, reinstall removed circuit packs and repeat the
procedure for the remaining circuit packs (except DS1s). If fuse blows after all
circuit packs have been removed, trouble is in the backplane.
30. STOP. YOU HAVE COMPLETED THIS PROCEDURE.
31.
NOTE:
Alarm may be caused by circuit packs inserted into the wrong slots or by
invalid or wrong switch settings on the TGS/TG3 circuit packs.
Are circuit packs installed in the correct slots (
rtrv-eqpt:
)?
If YES, then proceed to Step 34.
If NO, then continue with Step 32.
32. Remove circuit packs from wrong slots, check option switches (DLP-513) and
reinstall circuit packs into the correct slots.
33. STOP. YOU HAVE COMPLETED THIS PROCEDURE.
DLP-523