NEC Neax 2400 Imx System Operations And Maintenance Manual

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FAULT REPAIR PROCEDURES
9. FAN UNIT FAULT
This section explains the fault repair procedure where a fan in the Fan Unit (FANU) does not operate.
9.1 Check Point
(1) When repairing a FANU fault, exercise care about the following conditions. The fans (a total of 3) are
activated by operating the PWR SW key located on the PZ-M369. The conditions for starting the fan are
as follows:
 With PWR SW key for the fan set to ON position: Always operating
 With PWR SW key...

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9.2 Fan Unit Fault
Set the PWR SW key on the PZ-M369 to the ON position.
When the fan spins
Set PWR SW key to AUTO position, and short the thermal relay of the thermal
unit.
If the fan does not
operateCheck the connector cable between
the FANU and the thermal unit.
If the fan operates Replace thermal relay with a spare.
Disconnect the fan
connector of the cable for
the thermal unit.
Replace thermal relay with
a spare.
Connect the fan...

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10. TONE FAULT
This section explains the fault repair procedure when any of the various tones cannot be heard in the whole
system.
10.1 Check Point
When repairing a tone fault, consider that the tone generator circuit is equipped in the TSW circuit card
and supplies tone.
Figure 5-20 shows an example of the related trunking for dial tone connection.
Figure 5-20   Dial Tone Connection
TSW
DT
LC
Dial
Tone
ORT 

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10.2 Tone Fault
Replace the TSW circuit card with a spare
and check.
When only Hold Tone is faulty
If External Hold Tone source is in
useCheck the external equipment which sends out
hold tone.
Check cross connections on the MDF. Figure 5-
21 shows a block diagram of external hold tone
supply (optional).
Replace the EMA/PLO circuit
card with a spare.
Note:When system is 1-IMG
configuration, replace
EMA card. Otherwise,
replace PLO card.Set...

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Figure 5-21   External Hold Tone Supply Block Diagram Note:
If PH-CK16-A/PH-CK17-A is used, multiple connections are made between PLO#0 and PLO#1.
Refer to the description of PH-CK16-A or PH-CK17-A in the Circuit Card Manual.
PLO 1
External    Tone
 Source
(Option)
To Music 
Connector
for EMA
Card (IMG0)
MDF TSWM PIM 0 PIM 2 PIM 3
IMG1
PIM 1
Symbols
:  Circuit Card
:  Connector
Note
TSW 10
TSW 00
TSW 11
TSW 01
TSW 12
TSW 02
TSW 13
TSW...

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11. SYSTEM DOWN FAULT
This section explains the fault repair procedure when both the CPU and TSW systems are faulty. Figure 5-22
shows the sequence of repair for system down fault.
Figure 5-22   System Down Fault Repair Sequence
When cause for the fault cannot be identified:
Section 11.1When faulty circuit cards can be assumed from
system message: Section 11.2
Check power supply.
Minimize system configuration.
Execute system initialization...

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11.1 When Cause for Fault Cannot Be Identified
Check power supply circuits. Check voltage (DC: -48V, ±5V) at LOAD side 
of the rectifier.
Confirm that NFB (circuit breaker) on all PWR 
supplies is at ON position (UP side).
Check to see if there is any PWR supply to 
which the alarm lamp illuminates.
System Initialization by loading office data
and program data from the hard disk (Refer
to Chapter 6.)
Service connections such as...

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(1) Check by minimizing the system configuration
Mount only the basic circuit cards in CPU 
No. 0 system and initialize.Remove all circuit cards from CPU No. 0
system except the basic circuit cards.
Circuit cards to be mounted are as follows:
CPU, EMA, TSW, MUX
(EMA: PH-PC40, TSW: PH-SW12, MUX:
PH-PC36)
On the CPU Display Panel (DSP), set its SENSE
switch to “1.”
Press Reset (RST) button on the DSP.
CPU OPE lamp should be illuminated on...

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11.2 When Faulty Circuit Cards Can Be Assumed From System Message
Faulty Situation:
When the system is down with message [0-C] ~ [0-J] indicated, faulty circuit cards can be assumed from
the message detail data. Replace circuit cards with spares.
Replace  faulty  circuit  card  with  a  spare. Set MB switch UP and extract the circuit card
from its mounting slot.
Make necessary switch settings on the new
circuit card.
Set the MB switch UP...

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12. COMMON CHANNEL INTEROFFICE SIGNALING (CCIS) LINE FAULT
This section explains the fault repair procedure when any of the faults shown in Table 5-11 occur to a specific
CCIS line.
12.1 Check Point
When repairing a CCIS Line fault, consider the following items:
(1) Check alarm lamps on the CCH or CCT circuit card.
(2) Refer to Figure 5-23, and check the cable connection.
12.2 CCIS Line Control
The CCH/CCT circuit card controls the signal...