Avaya Definity SI Maintenance Manual page 1553

EXP-INTF (Expansion Interface Circuit Pack)
e. Perform Steps b, c, and d on the opposite end of the fiber and the
f. If the symptoms which were formerly occurring on the PPN
4. Determine if the problem is due to a defective Active Tone-Clock circuit
pack. Refer to the preceding list of symptoms to decide which network
contains the suspect Active Tone-Clock. See Warning.
!
!
a. On a High or Critical Reliability system in which the network
555-233-123
lightwave transceiver on the back of the EPN Expansion Interface
circuit pack slot.
NOTE:
If it is more convenient for you, execute Steps b, c, and d on
the EPN Expansion Interface circuit pack first.
Expansion Interface circuit pack are now occurring on the EPN
Expansion Interface circuit pack and vice versa, the fiber is defective
and should be replaced.
WARNING:
If you remove the EPN Expansion Interface circuit pack that is active
or that was active when the EPN was last in-service, then the 2A/3A
Tone-Clock circuit pack becomes the Active Tone-Clock. This
characteristic can be deceiving. Replacing or reseating the Active
EPN Expansion Interface circuit pack might restore the Expansion
Interface Links temporarily. However, if the 2B/3B Tone-Clock circuit
pack was really the source of the problem and not the Expansion
Interface circuit pack, then the Expansion Interface Link(s) goes down
again the next time a Tone-Clock switch to the 2B/3B Tone-Clock is
attempted (probably when the scheduled Tone-Clock switch occurs).
WARNING:
If, after all the Expansion Interface Links are restored, you suspect
the problem might have been due to a defective Tone-Clock circuit
pack, switch to this Tone-Clock at an appropriate time. If the
Tone-Clock circuit pack was the cause of the problem and the same
Expansion Interface circuit packs are in place, the same Expansion
Interface Link(s) goes down again.
containing the suspect Tone-Clock circuit pack is in-service:
Switch to the Standby Tone-Clock on this network. If the suspect
Tone-Clock circuit pack is defective, the Expansion Interface Link(s)
should be restored to service at this point. Switching back to the
defective Tone-Clock should make the same Expansion Interface
Link(s) go out-of-service. Such a Tone-Clock circuit pack is defective
and should be replaced as soon as possible. If switching
Tone-Clocks does not bring up the EPN, then this Tone-Clock is not
the source of the problem. Make sure to switch back to the original
Tone-Clock.
Issue 4 May 2002 10-767