NEC Neax 2400 Imx System Operations And Maintenance Manual

CHAPTER 4 NDA-24238
Page 304
Revision 3.0
UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
6. Fuse Replacement
The system uses the fuses shown in Figure 4-28 as a protection against an overload resulting from a short cir-
cuit.
Figure 4-28   Fuses Used by System
When excessive current is applied to a PWR circuit card, the related fuse is blown. The blown fuse after a fault
can be confirmed as shown in Figure 4-29.
Figure 4-29   Blown Fault Example
The purpose of fuses is to let them blow before the components are...

NDA-24238 CHAPTER 4
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Revision 3.0
UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
Figure 4-30 shows the location of fuses within the system. In Chapter 4-30, the fuses are indicated by   or  .
Figure 4-30   Fuse Locations Within System
NECNEAX 2400 IMS
PZ-M377
3.2A 5.0A
PZ-M3695.0A
..... .....
..... .....
PZ-PW92
5.0A 25A
25A
5.0A0.5A
PA-PW54
PA-PW555.0A
0.5A
25A
PBX [Front View] 

CHAPTER 4 NDA-24238
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UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
In the TSWM, the fuse shown in Figure 4-31 is used for the PWR SW (PH-PW14) card, which is housed in
Slot No. 00 and/or 01.
Figure 4-31   Fuse Location Within TSWM
 PH-PW14
(PWR SW)
FUSE:    15A
TSWM
PBX (IMG1)
Front View

 

NDA-24238 CHAPTER 4
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Revision 3.0
UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
Perform the procedure in Figure 4-32 to confirm the cause of the RGU fuse blown fault.
Figure 4-32   RGU Fuse Blown Fault Flowchart

Start
Visual check: No pin contacting
 or backboard melting?
OPE  Lamp (green) of 
each LC card  remains lit?
Replace the blown fuse with a new
one. The fuse is blown again?Yes
Yes
Yes
Yes YesNo
1.  Turn ON (UP) the MB key
     on the LC card.
2.  Remove the card from the PIM.
3....

CHAPTER 4 NDA-24238
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UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
Perform the procedure in Figure 4-33 to confirm the cause of the DC-48V fuse blown fault.
Figure 4-33   DC -48V Fuse Blown Fault Flowchart
Start
Visual check: No pin contacting
 or backboard melting?
OPE  Lamps (green) of 
LC/TRK/NCU cards remain lit?
Make sure in which module 
the fuse has blownNo
1.  Turn ON (UP) the MB key
     on the circuit card.
2.  Remove the card from the PIM.
3.  Replace the fuse with a new...

NDA-24238 CHAPTER 5
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Revision 3.0
FAULT REPAIR PROCEDURES
CHAPTER 5 FAULT REPAIR PROCEDURES
This chapter provides information on how to repair the fault(s) within the system. If any of the components or
equipment listed in Table 5-1 has a failure, move on to the repair procedure explained for each faulty condition.
Table 5-1  Fault Repair Procedure Quick Reference
FAULTY ITEM FAULTY SITUATION REFERENCE SECTION
Line Fault DP/PB Telephone Dial tone is not heard.Section 1.3, Line Fault - When Dial...

CHAPTER 5 NDA-24238
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FAULT REPAIR PROCEDURES
Speech System Fault Faults related to speech.Section 5.2, Speech Path System 
Fault - Fault Related to Speech
Dial tone is not heard.Section 5.3, Speech Path System 
Fault - When Dial Tone (DT) 
Cannot Be Heard
STBY side is faulty.Section 5.4, Speech Path System 
Fault - STBY Side Has Become 
Faulty
Control System Fault Fault occurs occasionally at the ACT side.Section 6.2, Control System Fault - 
Fault Occurs Intermittently
STBY side is...

NDA-24238 CHAPTER 5
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FAULT REPAIR PROCEDURES
1. LINE FAULT
This section explains the fault repair procedure in a case where only one specific station line is in any of the
faulty conditions listed in Ta b l e  5 - 2.
ISDN Line Fault  A specific DCH/PRT card is faulty.
 When the signal transmission line is a digital line, 
transmission/receiving of control signals cannot be 
performed.Section 13.3, Specific DCH/PRT 
Card Is Faulty and
Section 13.4, Fault of DCH, DTI, 
and Related...

CHAPTER 5 NDA-24238
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FAULT REPAIR PROCEDURES
1.1 Check Point
When repairing a line fault, consider the following items:
(1) Check alarm lamps on line circuit cards.
(2) When an outgoing call cannot be originated to a specific line/trunk or when an incoming call cannot be
terminated from a specific line/trunk, check Tenant Restriction Data (assigned via ATNR command) and
Route Restriction Data (assigned via ARSC command).
1.2 Line Control
Each line in a specific Line circuit (LC/ELC)...

NDA-24238 CHAPTER 5
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FAULT REPAIR PROCEDURES
1.3 Line Fault - When Dial Tone (DT) Cannot Be Heard
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 replacement is complete.
When OPE lamp on the LC circuit card
does not illuminateConfirm MB switch of the LC circuit card is in
ON position (UP).
Use ASDT command to confirm that station
data in the LC circuit card is assigned.
Replace the LC circuit card with a...