NEC UX5000 Hardware Manual

3 - 26 Chapter 3
Chapter 3 - Installing Extensions and Trunks
3.14.1.3 Troubleshooting CO Lines
Figure 3-16: CO Trunk Troubleshooting
Start
Verify the COIU blade
is functioning.
Is the Live
Status LED on
the COIU blade
flashing green?
Remove the blade and
insert another COIU
blade into the same
slot. Does it work?
Screen the problem
(whether problem
exists in UX5000 or
with central office).
The COIU blade
may need repair.
Main equipment
(chassis/CCPU) may
need repair.
Connect a test
terminal to the
CO line side. Is
dial tone heard?
Contact the CO to
investigate the line.
Verify if the problem is
with the main equipment
or the CO line by using a
test set before the
connection to the UX5000.
Is the wiring for the
cables correct?
Redo the wires between
the main equipment and
the CO line.
The COIU blade may
need repair.
Yes
Yes
Yes
No
No
No
Yes
No
* If it still does not work,
replace the cable(s) and/
or connectors.
Check system programming
for the extension. Refer to
the UX5000 Software
Manual if necessary.
Try placing a call on the
CO line. Does it work?
Stop
Yes
No
Is the blade blocked
in Program 90-05?
No
Is the Live
Status LED on
the COIU PCB
flashing green?
Yes
No
Release the Block
in Program 90-05
(enter 4) for the blade.
Stop
Can a call be placed
on the CO line?
Yes
Yes
No
Measure the loop
current on the line with
a digital voltmeter.
Is the PBXG grounding wire
from the UX5000 attached
and is there a proper
earth ground?
Yes
Connect the proper
grounding wires for
the UX5000.
No
Check the EXIFU cable
connection between
chassis with multiple
chassis systems.
No

NEC UX5000 Specifications

General

Brand	NEC
Model	UX5000
Category	Telephone
Language	English