NEC Neax 2400 Imx System Operations And Maintenance Manual

CHAPTER 5 NDA-24238
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Revision 3.0
FAULT REPAIR PROCEDURES
2.3 Trunk (ORT, SND, CFT) Fault
Note:If a circuit card is replaced because only one line is faulty, no
other lines in that circuit card can be used until the replace-
ment is complete.
When only one line is faulty Place the faulty line into make-busy state.
For ORT/SND, set MB switch of
each circuit to ON position.
For CFT, place it into make-busy
state using command MBTK.
Replace  the  circuit  card  with  spare. Set MB switch UP and...

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FAULT REPAIR PROCEDURES
2.4 Trunk (COT, TLT, DTI) Fault
Note 1:If a circuit card is replaced because only one line
is faulty, any other lines in that circuit card cannot
be used until the replacement is complete.
Note 2:If the polarities of the external line is reversed, it
is detected in the form of Trunk Ineffective Hold.
When OPE lamp on the trunk circuit card
does not illuminateConfirm that MB switch of the trunk circuit
card is in ON position (UP side)....

CHAPTER 5 NDA-24238
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FAULT REPAIR PROCEDURES
Check the faulty line on the MDF. If the C.O./Tie Line is in Loop Start system:
Isolate the faulty line to C.O. side and
to the system side.
Connect the test telephone to the C.O.
side.
Note 1:Check can be made
only on temporarily
opened C.O./Tie Lines.Confirm that Dial Tone (DT) is heard
and the call is connected to the desti-
nation party at the opposite office.
Note 2:Cross connection
methods are explained on
the following pages.If...

NDA-24238 CHAPTER 5
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FAULT REPAIR PROCEDURES
Note:
When performing loop-back connection tests on the trunks at the user’s office,
provide cross connection as follows:
(1) For a COT
 Set up a loop-back connection between the COT (C.O. Trunk) to be tested and station line.
 The trunk route must be assigned for Loop Start.
(2) For a TLT (for DID)
 Set up a loop-back connection between the Tie Line Trunk (TLT) to be tested and another TLT.
 If the TLT is a Direct Inward Dialing (DID)...

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FAULT REPAIR PROCEDURES
 If the TLT is a 2W E & M System, connect the related leads as shown below:
(3) For a DTI
 Set up a loop-back connection between the DTI Trunk to be tested and another DTI Trunk as shown
below:
 If the office is the PLO-source office, perform the tests by disconnecting the PLO and M-OSC. The
mode of the PLO becomes Self Operation Mode.
 When the loop-back test is performed at the time of PCM LOSS, FRM LOSS, or MERM LOSS alarm
lamp...

NDA-24238 CHAPTER 5
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Revision 3.0
FAULT REPAIR PROCEDURES
3. ATTCON/DESKCON FAULT
This section explains the fault repair procedure when a specific Attendant Console (ATTCON) is in any of the
following faulty conditions.
 No speech can be made.
 No operations can be made.
3.1 Check Point
When repairing an ATTCON/DESKCON fault, consider the following items:
(1) Check the cable connections on the backplane.
(2) When replacing the ATI circuit card for master ATTCON/DESKCON, the system is placed...

CHAPTER 5 NDA-24238
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FAULT REPAIR PROCEDURES
Figure 5-3   ATT Connector Cabling and Connector Leads Accommodation
LT5 LT11
PIM Backplane
MDFATTCON/
DESKCONLT11 is used when PA-CS33 is mounted in Slot 23.
LT5 is used when PA-CS33 is mounted in Slot 12.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23 47 34
35
36
37
38
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48 
BN4801 BN4800
BN4820 BN4821
TAS1B
TAS1A
BN4810
BN4830 BN4831BN4811
TAS0B
TAS0A
B2 A2
B3
A3 PA-CS33 Pin Assignment
Installation CableInstallation...

NDA-24238 CHAPTER 5
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FAULT REPAIR PROCEDURES
3.3 ATTCON/DESKCON Fault
Note 1:No speech can be made.
Note 2:While replacement of the ATI circuit card
for the master ATTCON/DESKCON is in
progress, the system is placed under Night
Mode.
On the ATTCON/DESKCON, LCHK 
(Lamp Check) key has been pressed but 
no lamps have illuminated.Check the ATT connector cable between the
ATTCON/DESKCON and the PBX.
When the OPE lamp of the ATI (PA-
CS33) circuit card does not illuminateConfirm that MB...

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FAULT REPAIR PROCEDURES
Note:
No operations can be made.
Replace the ATTCON/DESKCON with a
spare.Set the MB switch of ATI PA-CS33 circuit
card UP.
If the circuit card is equipped with a fuse,
remove the fuse.
Disconnect the CHAMP connector of the
ATTCON/DESKCON and replace the
ATTCON/DESKCON.
If the circuit card is equipped with a fuse,
insert the fuse into its position.
Set the MB switch of the ATI circuit card
DOWN.
Confirm the PA lamp illuminates on the...

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FAULT REPAIR PROCEDURES
4. UNIT FAULT
This section explains the fault repair procedure in a case where any of the faults shown in Table 5-6 has oc-
curred to all the line/trunk circuit cards mounted in a specific unit. Figure 5-4 shows the range of units.
Figure 5-4   Range of Units Table 5-6  Unit Fault Situation
FAULT SITUATION REFERENCE SECTION
Noise, one-way speech, no tone.
Even if dialing has been made, dial tone does not stop.Section 4.2, Unit Fault -...