AT&T System 25 - Manual (Page 268)

MAINTENANCE
6. If “no loop current on outgoing call” is displayed, either of the above
conditions could be true. It is more likely, however, that the facility is
d o w n .
7. Place an outside call on the line using the trunk test call procedures
listed in outgoing Trunk Problems. If you get fast busy tone, switch
trunk ports and try again.
8. If the problem does not move, replace the Loop Start CP.
9. If the problem moves, the fault is with the CO. Notify CO personnel
through the proper channels.
Error Log Interpretation: Ground-Start Trunks
Procedures:
1.
2.
3.
4.
5.
6.
7.
Check the Error Log for messages pertaining to ground-start trunks.
If “no loop current on incoming call” is displayed, no loop current
was detected on an incoming call. The CP detected ringing, but not
loop current when it closed the loop. In this case, the CO facility is
probably good, but either the current sensor on the CP is faulty or
the CO battery circuit is faulty.
Switch trunk ports and see if the problem moves to the new ground-
start trunk.
If the problem does not move, replace the Ground Start CP.
If the problem moves, the fault is with the CO. Notify CO personnel
through the proper channels.
If “fault on outgoing seizure” is displayed, either of the two
conditions is true. The first condition is that the trunk CP did not
detect loop current as in the case of the “no loop current on
incoming call” message. The second condition is that the trunk CP
did not detect tip ground. This could be either a problem with the
CO or the ground detector on the CP.
Place an outside call on the line using the trunk test call procedures
listed under Outgoing Trunk Problems. If you get fast busy tone,
switch trunk circuits and try again.
4-91