NEC Neax 2400 Ipx System Operations And Maintenance Manual

NDA-24307 CHAPTER 4
Page 353
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UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
STEP 9 Take off the four screws and remove the Cooling Fan from the CPR. Refer to Figure 4-25.
STEP 10 Fasten the new Cooling Fan and CPR with the removed screws. Then, connect the fan cable
again. Refer to Figure 4-25.
STEP 11 Connect the fan cable again and insert the CPR back into the LPM. Refer to Figure 4-23 and
Figure 4-24.
STEP 12 Fasten the CPR and LPM with the four screws.
STEP 13 Connect the disconnected power, bus,...

CHAPTER 4 NDA-24307
Page 354
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UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
7. FUSE REPLACEMENT
The system uses the fuses shown in Figure 4-26 as a protection against an overload resulting from a short
circuit.
Figure 4-26   Kind of Fuse
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 4-27.
Figure 4-27   Fuse After Blown Fault
The purpose of fuses is to let them blow before the components are damaged. If...

NDA-24307 CHAPTER 4
Page 355
Issue 1
UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
The following figures show the location of fuses within the system. In the figures, the fuses are indicated 
by  or  .
Figure 4-28   Fuse Locations in LPM/PIM/FANU/BASEU
PIM
LPM
Note
Note
 
NECNEAX 2400 IMS
    
PZ-M377
3.2A 5.0A
  
 
PZ-M 3695.0A
..... .....
..... .....
PZ-PW92
5.0A
25A
PA-PW54-A/
PA-PW55-A/5.0A
0.5A
25A
PBX [Front View]
PA-PW54-B
PA-PW55-B
5.0A
0.5A
25A 

CHAPTER 4 NDA-24307
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UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
In the TSWM, the fuse shown in Figure 4-29 is used for the PWR SW (PH-PW14) card, which is housed in
Slot No. 00 and/or 01.
Note:The PH-PW14 card is also used in Slot No. 00 and/or 01 of ISWM.
Figure 4-29   Fuse Location on PWR SW Card (TSWM/ISWM)
 PH-PW14
(PWR SW)
FUSE:    15A
TSWM
PBX (IMG1/2)
Front View 

NDA-24307 CHAPTER 4
Page 357
Issue 1
UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
Perform the procedure in Figure 4-30 to confirm the cause of the RGU fuse blown fault.
Figure 4-30   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.  Replace the fuse...

CHAPTER 4 NDA-24307
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UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE
Perform the procedure in Figure 4-31 to confirm the cause of the DC-48V fuse blown fault.
Figure 4-31   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 one.
Turn ON...

NDA-24307 CHAPTER 5
Page 359
Issue 1
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 Referenc e
FAULTY ITEM FAULTY SITUATION REFERENCE SECTION
Line Fault DP/PB Telephone Dial tone is not heard.Section 1.3, Line Fault - When Dial 
Tone (DT) Cannot Be Heard...

CHAPTER 5 NDA-24307
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FAULT REPAIR PROCEDURES
Speech System Fault 
(LN)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 (LN) - STBY Side Has 
Become Faulty
Speech Path System Fault
(Whole System/ISW)Fault related to speech.Section 6.2, Speech Path System 
Fault (Whole System/ISW) - Fault...

NDA-24307 CHAPTER 5
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FAULT REPAIR PROCEDURES
System Down Fault Cause for the fault cannot be identified.Section 12.1, When Cause for Fault 
Cannot Be Identified
The faulty circuit card can be detected.Section 12.2, When Faulty Circuit 
Cards Can Be Assumed From 
System Message
CCIS Line FaultA Specific CCH/CCT card is faulty. When the signal 
transmission line is a digital line, transmission/
receiving of control signals cannot be performed. 
When the signal transmission line is an...

CHAPTER 5 NDA-24307
Page 362
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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 Table 5-2.
Table 5-2  Line Fault Situation
FAULTY SITUATION REFERENCE SECTION
When Dial Tone cannot be heardSection 1.3, Line Fault - When Dial Tone (DT) Cannot Be Heard
When dialing results in a wrong connectionSection 1.4, Line Fault - When Dialing Results in a Wrong 
Connection
When the...