NEC Electra Elite 192, Hardware Manual

Page: 352 / 369

Issue 6 Electra Elite
9 - 10 System Maintenance
. .
.
Not Cleared
No or Intermittent CO/PBX Ring
Test to see if problem occurs
on one line or several lines.
One Line
Several Lines
Occurrence?
See if problem occurs on
all Multiline Terminals
Assigned Ringing.
C h e ck M e m o ry B lo cks 4 -0 1 a n d 4 -0 2 to
ensure that line is programmed to
ring on an installed station.
Not all terminals
All Terminals
Occurrence?
Yes
Yes
Yes
Yes
No
No
No
No
No
Yes
Ringing
Assigned?
Program ring assignment
and test.
Corrected?
End.
Replace one terminal
that has problems.
Still have
Problem?
Corrected?
See if affected lines
can be isolated to
One COI(8)-U10 ETU.
Corrected?
No
Yes
Basic KSU?
Replace Ribbon cable
between KSUs.
Check whether or not
affected lines can be
isolated to one KSU.
Return defective Multiline
Terminal for repair.
Reset/ Replace
COI(8)-U10 ETU.
1 COI(8)-U10
ETU?
Program station for off-hook and
day/night ring, deny DND feature,
and test again.
Perform the following tests:
1. Measure CO ring voltage with AC meter
(100 Vac 20 Hz) at the MDDF.
2. Perform Second Initialization.
3. Place external ringer in front of system on
worst case CO line. Check if customer
can hear external ringer at times when the
system does not detect ringing on this line.
4. If problem is not solved, perform First
Initialization and replace CPUB( )-U10.
Test system using default program.
Done.
Done.
C1
Cleared