NEC Neax 2400 Ipx System Operations And Maintenance Manual

NDA-24307 CHAPTER 5
Page 383
Issue 1
FAULT REPAIR PROCEDURES
3.3 ATTCON/DESKCON Fault
Note:No speech can be made. 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, Lamp Check 
(LCHK) key has been pressed but no lamps 
have illuminated.Check the ATT connector cable between the 
ATTCON/DESKCON and the PBX.
When OPE lamp of the ATI (PA-CS33) 
circuit card does not illuminateCheck to see if MB switch of the...

CHAPTER 5 NDA-24307
Page 384
Issue 1
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...

NDA-24307 CHAPTER 5
Page 385
Issue 1
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
occurred 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 (LN0/1/2/3)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...

CHAPTER 5 NDA-24307
Page 386
Issue 1
FAULT REPAIR PROCEDURES
4.1 Check Point 
When repairing a unit fault, consider the following items:
(1) Speech paths and control paths in the unit are connected to line/trunks via the MUX circuit cards. Be sure
to check the alarm lamps on the MUX circuit cards, and check to see if the front cable between each MUX
circuit card and TSW circuit card is connected correctly. Figure 5-5 and Figure 5-6 show the block
diagram within the unit.
(2) The MUX circuit cards are...

NDA-24307 CHAPTER 5
Page 387
Issue 1
FAULT REPAIR PROCEDURES
Figure 5-6   Unit Control Block Diagram (Single Configuration)
Figure 5-7   MUX Card Locations (LN0/1/2/3)
LC/TRK
LC/TRK
PM
Line/
Trunk
Circuit Card
MUX X
To
TSW/Clock
Speech
Path
(A)
Control of
CPU
MUX
MUX (PH-PC36) card is mounted
in Slot No. 13 and/or 14 of each
PIM.
MUX 0MUX 1UNIT = 2
UNIT = 3 PIM 3
13 IMG0/1/2/3
Front View14
MUX 0MUX 1UNIT = 0
UNIT = 1 PIM 213
14
MUX 0MUX 1UNIT = 2
UNIT = 3 PIM 113
14
MUX 0MUX 1UNIT = 0
UNIT = 1 PIM 013
14 

CHAPTER 5 NDA-24307
Page 388
Issue 1
FAULT REPAIR PROCEDURES
4.2 Unit Fault - Fault Related to Speech
Faulty Situation:
Noise, one-way speech, no tone, etc. occurs only within a unit.
Even if dialing has started, dial tone does not stop.
(1) For Dual Configuration
Check by replacing the MUX (PH-PC36)
circuit card.Replace the MUX circuit card referring to 
Section 3.3.2, MUX Card Replacement 
Procedure, Chapter 4.
After replacement of the MUX
circuit card, make a station-to-
station call in the faulty...

NDA-24307 CHAPTER 5
Page 389
Issue 1
FAULT REPAIR PROCEDURES
Check the line/trunk circuit cards mounted
in the unit to see if t ey are faulty. 
Perform this check on an individual basis.Set the MB switch of the line/trunk circuit card
UP and extract it from its mounting slot.
Make a station-to-station call and see if a fault
occurs.
If the fault has stopped occurring,
the circuit card extracted at that
time is faulty. Replace the circuit
card with a spare.
If the fault continues, check the
next circuit...

CHAPTER 5 NDA-24307
Page 390
Issue 1
FAULT REPAIR PROCEDURES
(2) For Single Configuration
Check by replacing the MUX (PH-PC36)
circuit card.Replace the MUX circuit card by referring to
Section 3.3.2, MUX Card Replacement
Procedure, Chapter 4.
After replacement of the MUX
circuit card, make a station-to-
station call in the faulty unit and
see if speech is normal.
Check by replacing the TSW circuit card. Replace  the  TSW  circuit  card  referring  to
Section 2.3.2, TSW Card Replacement
Procedure, Chapter...

NDA-24307 CHAPTER 5
Page 391
Issue 1
FAULT REPAIR PROCEDURES
Check the line/trunk circuit cards mounted
in the unit to see if they are faulty.
Perform this check on an individual basis.Set the MB switch of the line/trunk circuit
card UP and extract it from its mounting slot.
Make a station-to-station call and see if a fault
occurs.
If the fault has stopped, the
circuit card extracted at that time
is faulty. Replace the circuit card
with a spare.
If the fault continues, check the
next circuit card....

CHAPTER 5 NDA-24307
Page 392
Issue 1
FAULT REPAIR PROCEDURES
4.3 Unit Fault - When Dial Tone (DT) Cannot Be Heard
Faulty Situation:
Dial Tone (DT) cannot be heard except within a unit.
[4-T] Both MUX Failure / [4-S] MUX 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.
(1) For Dual Configuration
Check to see if the...