NEC Neax 2400 Ipx System Operations And Maintenance Manual

NDA-24307 CHAPTER 5
Page 403
Issue 1
FAULT REPAIR PROCEDURES
(2) For Single Configuration
Check to see if the fault occurs by
replacing TSW circuit cards one by one.Replace the TSW circuit card referring to
Section 2.3.2, TSW Card Replacement
Procedure, Chapter 4.
Check to see if a station-to-station connection
can be set up and identify a TSW circuit card
responsible for the fault.
Perform the above check by extracting the TSW
circuit cards individually.
Check to see if the fault occurs by
replacing MUX...

CHAPTER 5 NDA-24307
Page 404
Issue 1
FAULT REPAIR PROCEDURES
When the PLO (PH-CK16-A/17-A)/CLK
(PH-CK18) circuit card is mounted for
digital interface, replace the PLO circuit
card with a spare and check it.Set MB switch of the PLO/CLK circuit card
to UP side.
Confirm OPE lamp on the PLO/CLK circuit
card goes out.
Extract PLO/CLK circuit card from its
mounting slot.
Set MB switch UP and insert the new PLO/
CLK circuit card into its mounting slot.
Set MB switch DOWN.
Confirm the OPE lamp on the new...

NDA-24307 CHAPTER 5
Page 405
Issue 1
FAULT REPAIR PROCEDURES
5.3 Speech Path System Fault - When Dial Tone (DT) Cannot Be Heard
Faulty Situation:
Dial Tone (DT) cannot be heard.
[1-A] Both TSW Failure (Permanent)
[1-E] Both TSW Clock Failure
[4-C] Both TSW Ready Failure
[23-Y] MUX Clock Failure
Note:For dual system configuration, if a system message indicates that both systems are faulty, first repair
the fault in the indicated system and then proceed to repair the PIM in the other system.
Check to...

CHAPTER 5 NDA-24307
Page 406
Issue 1
FAULT REPAIR PROCEDURES
5.4 Speech Path System Fault (LN) - STBY Side Has Become Faulty
Faulty Situation:
A fault occurred in the STBY side of the dual configuration system.
[1-B] TSW Failure (Permanent)
[1-D] TSW Write Failure
[1-F] TSW Clock Failure
[4-D] TSW Ready Failure
Check to see if the TSW circuit card
(STBY) is making poor contact.Set the TSW MBR switch of the TSW circuit
card UP.
Set the MB switch of the TSW circuit card UP
and extract the circuit card...

NDA-24307 CHAPTER 5
Page 407
Issue 1
FAULT REPAIR PROCEDURES
Faulty Situation:
Fault related to speech such as noise, one-way speech, no-speed, etc. occurs.
Even if dialing started, Dial Tone (DT) does not stop.
[1-C] Both TSW Write Failure
[1-D] TSW Write Failure
Check to see if fault occurs by extracting
TSW circuit cards one by one.Replace the TSW circuit card referring to
Section 2.3.2, TSW Card Replacement
Procedure, Chapter 4.
Set the TSW circuit card into ACT mode. Refer
to Section 12, Chapter...

CHAPTER 5 NDA-24307
Page 408
Issue 1
FAULT REPAIR PROCEDURES
6. SPEECH PATH SYSTEM FAULT (WHOLE SYSTEM/ISW)
This section explains the fault repair procedure when any of the fault shown in Table 5-8 has occurred in a
whole system.
6.1 Check Point
System messages pertaining to whole system fault are shown in Figure 5-9. Check the system messages.
Figure 5-9   System Messages Related to Speech Path System Fault (Whole System/ISW)Table 5-8  Speech Path (TSW) System Fault Situation (LN)
FAULTY SITUATION...

NDA-24307 CHAPTER 5
Page 409
Issue 1
FAULT REPAIR PROCEDURES
6.2 Speech Path System Fault (Whole System/ISW) - Fault Related to Speech
Replace the TSW card mounted in the 
ISWM with a spare.Replace the TSW card by referring to Section 
4.3.2, TSW Card Replacement Procedure, 
Chapter 4.
Place the TSW circuit card on the ACT mode.
Refer to Section 12, Chapter 6.
After replacement of the TSW card, 
make a station to station call and 
check and see if a fault occurs.
When a fault occurs in the whole system,...

CHAPTER 5 NDA-24307
Page 410
Issue 1
FAULT REPAIR PROCEDURES
6.3 Speech Path System Fault (Whole System/ISW) - ACT side becomes Faulty 
Intermittently
Check by replacing related circuit cards of 
the ACT mode with a spare.Related circuit cards: 
IOGT (Section 4.3.1, Chapter 4)
TSW (Section 4.3.2, Chapter 4)
HSW (Section 4.3.3, Chapter 4)
Set the faulty system on the STBY mode.
Refer to Section 12, Chapter 6.
On the circuit card, set its MB switch UP and 
extract the circuit card out of its mounting...

NDA-24307 CHAPTER 5
Page 411
Issue 1
FAULT REPAIR PROCEDURES
6.4 Speech Path System Fault (Whole System/ISW) - STBY side becomes Faulty 
Intermittently
Check by replacing related circuit cards of 
the STBYmode with a spare.Related circuit cards: 
IOGT (Section 4.3.1, Chapter 4)
TSW (Section 4.3.2, Chapter 4)
HSW (Section 4.3.3, Chapter 4)
Set the faulty system on the STBY mode.
Refer to Section 12, Chapter 6.
On the circuit card, set its MB switch UP and 
extract the circuit card out of its mounting...

CHAPTER 5 NDA-24307
Page 412
Issue 1
FAULT REPAIR PROCEDURES
6.5 PLO Fault
Replace the faulty PLO circuit card with a 
spare.Set MB switch of the PLO circuit card UP and 
extract the circuit card from its mounting slot.
Make necessary switch settings on the new PLO 
circuit card.
Set MB switch UP and insert the circuit card 
into its mounting slot.
Set MB switch DOWN.
Confirm that no noise generates in a station- 
to-station connection.If the system has been operated by the STBY 
side, set MB switch on...