ATT System 25 Installation And Maintenance Manual

							MAINTENANCE
Figure 4-10.TDM Signal Designations on Cabinet Backplane
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							MAINTENANCE
Figure 4-11.Power Designations onCabinet Backplane
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							_ MAINTENANCE
Each of the 12 universal carrier slots has 48 pins on the backplane for
connection to station and trunk ports. The 48 pins are divided into eight
groups of 6 pins each, one group for each port circuit. Lead
designations consist of the lead name suffixed by the group number (for
example, TA.2, RA.2). Specific functions depend on the type of port CP.
Table 4-D provides the 25-pin connector to backplane pin designations.
Typical backplane problems include power supply failure, sudden failure
of one or more CPs or system troubles that cannot be isolated to a
specific maintenance unit.
Backplane troubles are usually caused by bent or broken pins. A visual
inspection of the backplane may be adequate to determine if pins are
bent or broken. This inspection may require removing one or more CPs
Backplanes cannot be repaired in the field. When a backplane is faulty,
the entire cabinet (but not the CPsin the cabinet) must be replaced.
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							MAINTENANCE
Table 4-D.
25-Pair Connector to Backplane Designations
25-Pin-Conn.
Call
Proc
Pin No.
Wire
ColorGS
Trunk
ZTN76LS
Trunk
ZTN77Tip Ring
Line
ZTN78ATL
Line
ZTN79MET
Line
TN735Backplane
Pin No.
(Slots 1-12)
26
1
27
2
28
3
29
4
30
5
31
6
32
7
33
8
34
9
35
10
36
11
37
12
38
13
39
14
40
15
41
16
42
17
43
18
44
19
45
20
46
21
47
22
48
23
49
24
50
25W-BL
BL-W
W-O
O-W
W-G
G-W
W-BR
BR-W
W-S
S-W
R-BL
BL-R
R-O
O-R
R-G
G-R
R-BR
BR-R
R-S
S-R
BK-BL
BL-BK
BK-O
O-BK
BK-G
G-BK
BK-BR
BR-BK
BK-S
S-BK
Y-BL
BL-Y
Y-O
O-Y
Y-G
G-Y
Y-BR
BR-Y
Y-S
S-Y
V-BL
BL-V
V-O
O-V
V-G
G-V
V-BR
BR-V
V-S
S-VRDA
SGA
DCDA
DTRA
TDA
RDB
SGB
DCDB
DTRB
TDB
RDC
SGC
DCDC
DTRC
TDC
RDD
SGD
DCDD
DTRD
TDDT1  T1  T1
R1  R1  R1
T2  T2  T2
R2  R2  R2
T3  T3  T3
R3  R3  R3
T4  T4  T4
R4  R4  R4
T5  T5  T5
R5  R5  R5T1
R1
CT1
CR1
P-1
P+1
T2
R2
CT2
CR2
P-2
P+2
T3
R3
CT3
CR3
P-3
P+3
T4
R4
CT4
CR4
P-4
P+4
T5
R5
CT5
CR5
P-5
P+5
T6
R6
CT6
CR6
P-6
P+6
T7
R7
CT7
CR7
P-7
P+7
T8
R8
CT8
CR8
P-8
P+8
GND
GNDT1
R1
BT1
BR1
LT1
LTR1
T2
R2
BT2
BR2
LT2
LTR2
T3
R3
BT3
BR3
LT3
LTR3
T4
R4
BT4
BR4
LT4
LTR4102
002
103
003
104
004
105
005
106
006
107
007
108
008
109
009
110
010
111
011
112
012
113
013
302
202
303
203
304
204
305
205
306
206
307
2007
308
208
309
209
310
210
311
211
312
212
313
213
300
200 T6  T6  T6
R6  R6  R6
T7  T7  T7
R7  R7  R7
ETU48ETUGDETU48ETUGD
ETU48ETUGDETU48ETUGD
T8  T8  T8
R8  R8  R8
GND  GND  GND
GND   GND  GNDGND
GND
Note: TN747 is same as ZTN76 and ZTN77. TN762 is same as ZTN79.
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							MAINTENANCE
Table 4-D.25-Pair Connector to Backplane Designations Contd)
25-Pin-Conn..
Pin No.Wire
ColorDID
Trunk
TN753Tie
Trunk
TN760BAux.
Trunk
TN763Data
Line
TN726Analog
Line
TN742Analog
Line
TN746BDS1
Interface
TN767Backplane
Pin No.
(Slots 1-12)
26
1
27
2
28
3
29
4
30
5
31
6
32
7
33
8
34
9
35
10
36
11
37
12
38
13
39
14
40
15
41
16
42
17
43
18
44
19
45
20
46
21
47
22
48
23
49
24
50
25W-BL
BL-W
W-O
O-W
W-G
G-W
W-BR
BR-W
W-S
S-W
R-BL
BL-R
R-O
O-R
R-G
G-R
R-BR
BR-R
R-S
S-R
BK-BL
BL-BK
BK-O
O-BK
BK-G
G-BK
BK-BR
BR-BK
BK-S
S-BK-
Y-BL
BL-Y
Y-O
O-Y
Y-G
G-Y
Y-BR
BR-Y
Y-S
S-Y
V-BL
BL-V
V-O
O-V
V-G
G-V
V-BR
BR-V
V-S
S-VT1
R1
T2
R2
T3
R3
T4
R4
T5
R5
T6
R6
T7
R7
T8
R8
GND
GND
T1
R1
T11
R11
E1
M1
T2
R2
T12
R12
E2
M2
T3
R3
T13
R13
E3
ME
T4
R4
T14
R14
E4
M4T1
R1
SZ1
SZ11
S1
S11
T2
R2
SZ2
SZ12
S2
S12
T3
R3
SZ3
SZ13
S3
S13
T4
R4
SZ4
SZ14
S4
S14TXT1
TXR1
PXT1
PXR1
TXT2TXR2
PXT2
PRT2
TXT3TXR3
PXT3
PXR3
TXT4TXR4
PXT4
PXR4
TXT5TXR5
PXT5
PXR5
TXT6TXR6
PXT6
PXR6
TXT7TXR7
PXT7
PXR7
TXT8TXR8
PXT8
PXR8GND
GNDT1
R1
T2
R2
T3
R3
T4
R4
T5
R5
T6
R6
T7
R7
T8
R8GND
GND
T1
R1
T2
R2
T3
R3
T4
R4
T5
R5
T6
R6
T7
R7
T8
R8
T9
R9
T10
R10
T11
R11
T12
R12
T13
R13
T14
R14
T15
R15
T16
R16
GND
GND
102
002
103
003
104
004
105
005
106
006
107
007
108
008
109
009
110
010
111
011
112
012
113
013
302
202
303
203
304
204
305
205
306
206
307
207
308
208
309
209
310
210
311
211
312
212
313
213
300
200 L1*
L1L0
L0
LBACK 2
LBACK 1
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							MAINTENANCE
8 CABLE LENGTH
CONNECTOR 1
CONNECTOR 0
CONNECTOR 2
STOCKLIST
DESCRIPTION
25-PR PLUG
8-FT, 8-PR, 24-GC, CABLE
25-PR RECEPTACLE
SPACER (NOTE 1)
NOTES:
1.
2.
3.
INSTALL SPACER AT CONNECTOR CABLE CLAMP TO ENSURE PROPER
CABLE RETENTION.
ITEMS 1 AND 3 SHALL BE EQUIPPED WITH SCREWS TO FACILITATE
ASSEMBLY TO B25A CABLES.
LABEL CONNECTORS AS SHOWN: 0,1,2.
CONN 0CONN 2
2626
11
2729
24
2832
37
2935
4
10
3438
9
13
3541
1016
3644
1119
3747
1222WIRING LIST
CONN 0
CONN 1
38
26
131
39
29
144
40
32
157
4135
16
10
4638
2113
4741
2216
48
44
23
19
4947
24
22
Figure
November 1995
4-11a.853Adapter
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							MAINTENANCE
Emergency Transfer Unit Trouble
If the Emergency Transfer Unit (ETU) will not enter the power failure mode, do
the following steps:
1.
2.
3.
Unplug the cable bringing the control signal from port 7 or 8 on the
CPU/Memory CP to the ETU. This cable terminates in a modular jack
that is inserted in a modular plug labeled CPU on the left-hand side of
the ETU.
If the ETU goes into the power failure mode, the CPU/Memory CP is
probably faulty or a wiring problem exists. Plug the cable back in, then
reset the CPU/Memory CP by removing and restoring power to the
system. If the ETU still does not go into the power failure mode, the
CPU/Memory CP must be replaced.
If the ETU does not go into the power failure mode after the control
cable was unplugged in Step 1, the ETU is faulty and must be replaced.
If the ETU remains in the power failure mode continuously (preventing normal
operation of the system), follow these steps:
1.
2.
3.
4.At the ETU, unplug the cable bringing the control signal from the
CPU/Memory CP.
Using a modular jack breakout box and voltmeter, check to see that 48
volts are present between pins 1 and 2 and pins 3 and 6 of the control
cable from the CPU/Memory CP.
If the above voltages are present, the ETU is faulty and should be
replaced.
If the above voltages are not present, either the CPU/Memory CP or the
cable is faulty and should be replaced.
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							MAINTENANCE
CLEARING USER-DETECTED TROUBLES
User-reported troubles are usually associated with voice or data terminal
equipment or trunks.They can result from system-detected errors and are
often solved by clearing system error conditions or alarms.
This section presents trouble-clearing techniques and procedures for user-
reported troubles.
Maintenance routines for data terminals and Asynchronous Data Units (ADUs)
are not contained in this section (although some basic routines for clearing
administration equipment troubles are included). Manuals covering data
terminals and data modules are listed in Section 5, “References.”
Maintenance for auxiliary devices that are customer provided is the
responsibility of the user.
Administration Equipment Troubles
Administration equipment that is connected to the system on a dedicated
basis includes the System Administration Terminal (SAT), Station Message
Detail Recording (SMDR), and Digital Tape Unit.
Symptoms: .
Terminal dead or functioning intermittently. Messages contain
“garbage” characters.
Procedures:
1.
2.
3.
4.
Check ac power connection.
Check cabling to cabinet.
Check administered settings for SAT (see the Administration Manual).
Settings should be for 8-bit word length, no parity, space (0) for bit
8;baud rate 1200.
Check pin 20 of
steady at greater
(ground).EIA connector for DTR signal. Signal should be
than or equal to +3.0 volts with respect to pin 7
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							MAINTENANCE
Note:For problems with administration equipment that is not
connected on a dedicated basis, refer to the Terminal
Operations Manual, 555-540-710.
Time-Keeping Troubles
Symptoms:
Clock
Procedures:
1.Resetdoesn’t reflect current time or date.
clock from SAT (see the Administration Manual). Clock has
tolerance of plus or minus 3 minutes per month. Variances outside
this range indicate a faulty clock and require replacement of the
CPU/Memory CP. Time must be reset
Voice Terminal and Wiring Troubles
Symptoms:
Intermittent voice terminal troubles.
Procedures:
1.
2.
3.
4.
5.
Swap a known good terminal withfor Daylight Savings Time.
the questionable terminal to
determine if problem is localized to a single terminal. If local power
is provided, check power supply.
if troubles do not persist, problem is localized to single terminal.
Replace faulty terminal.
If good terminal does not work properly, fault is in wiring or circuit
pack (CP).
Check other terminals connected to same CP. If other terminals are
working properly, fault is probably in wiring. Swap wiring between
Station Interconnect Panel and terminal to verify wiring problem.
Check and clear any wiring problems.
If other terminals connected to same CP are not working properly,
fault is probably in CP.
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							6.
7.
8.
9.
Voice
Check CP translations from the SAT to be sure that this CP has
Check LEDs on CP. The red LED will be lighted if a fault on the CP
affects all ports. Also, the red LED may be lighted if one or a few
ports are faulty.
Check Error Log for relevant messages.
Reseat the CP even if the red LED is dark. (See “Reseating and
Replacing Circuit Packs” under “Routine Maintenance” in this
section.) Replace the faulty CP.
Transmission Troubles
Symptoms:
Voice terminals not receiving tones.
Procedures:
1.Check
2. Check
Symptoms:that green LED on power supply is lighted.
power supply for voltages.
Many single-line sets or multibutton electronic telephone (MET) sets
are not able to dial correctly even though they are able to receive
calls.
Procedures: Using a single-line voice terminal, test the touch-tone registers
as follows:
1.Go off-hook, and dial  *3 and the 2-digit number (01 through 12) of
the touch-tone receiver to be tested. Receivers 01 through 04 are
on the ZTN85 or ZTN131 (R3) CP. Receivers 05 through 12 are
present only if the system has TN748B CP(s).
You will hear busy tone if the receiver is in use. You will
hear reorder tone if you misdialed or addressed a receiver
not in the system (for example, you dialed *305 and the
system does not have a TN748B CP). Try again.
4-83