NEC UX5000 - Troubleshooting ISDN Lines

Chapter 3 - Installing Extensions and Trunks
Chapter 3 3 - 27
3.14.1.4 Troubleshooting ISDN Lines
Figure 3-17: BRI Line Troubleshooting
Start
Verify the BRIU blade
is functioning.
Is the Live Status
LED on the BRIU
blade flashing green?
Remove the blade and
insert another BRIU
blade into the same slot.
Does it work?
Verify wiring between
main equipment and
CO line and between
the two UX5000
chassis (if installed).
The BRIU blade may
need repair.
Main equipment
(chassis/CCPU) may
need repair.
Is the cable
wiring correct?
DSU may need repair.
Insert another BRIU blade
into the same slot in the
CCPU. Does it work?
T-Point portion of the external
DSU may need repair.
The BRIU blade
may need repair.
Yes
Yes
No
Yes
No
Yes
No
The main equipment
(chassis/CCPU) may
need repair.
* If it still does not work,
replace the cable(s) and/
or connectors.
Yes
No
Is the ISDN Layer1
link established
(LD2, LD3 flashing)
on the BRIU blade?
No
Redo the wires
correctly.
No
Request the CO
perform a
loopback test of
the DSU. Any
problems found?
Yes
If an external DSU is
used, connect the
ISDN terminal to the
T-Point. Is it possible
to make a call?
No
Yes
Check system programming
for the extension. Refer to the
UX5000 Software Manual if
necessary. Is it possible to
make a call?
No
Stop
Yes
Release the Block
in Program 90--05
(enter 4) for the blade
and recheck operation.