NEC NEAX 2000IVS2, Maintenance Manual, Page: 133 / 156

CHAPTER 2 TROUBLESHOOTING
Fault Diagnosis and Troubleshooting
NEAX2000 IVS
2
Maintenance Manual
ND-70926 (E), Issue 3.0
Page 125
Dial Tone is not returned from
distant office.
In case of COT card (1) Disconnect the trunk from the line
on the MDF.
(2) Connect a test telephone set to the
C.O. line (distant office side) on the
MDF.
(3) If Dial Tone is returned by going off-
hook on the test telephone set,
check for trouble with wiring on the
MDF and the trunk card.
(4) If not, there is a problem with the
distant office or the C.O. line.
(1) Trunk card.
In case of ODT card (1) Disconnect the trunk from the line
on the MDF.
(2) To perform a Loop Back Test, make
a back to back connection of the
trunk card and another trunk within
the system at the MDF.
NOTE: This test only works when the
trunks are assigned for type V
operation.
A
B
CHECK
SW MDF
TRUNK
TO DISTANT OFFICE
TEST TELEPHONE SET
REPLACE
CHECK