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MAINTENANCE
Table 4-C. Circuit Pack Voltage–Symptoms
Voltage/
+5 volts
-5 volts
-48 Volts
Circuit Pack (Notes)
No+5 V
No-5 V
No-48 V
Call Proc. (ZTN82,
x
System Failure
x
EIA Failure
x
ETU Activated
ZTN1 28) for RI
Memory (ZTN81,
x
System Failure
-
- -
-
ZTN1 27) for RI
CPU/Memory (ZTN129,
x
System Failure
x
EIA Failure
x
ETU Activated
for R2, ZTN130
for R3)
STARLAN (ZTN84)
x
CP Failure
x
CP Failure -
-
Service Ckt (ZTN85
x
System Failure
- - - -
or ZTN131 (R3)
Hybrid Line (ZTN79)
x
CP Failure
x
No Voice
x
Station OS
Tip/Ring (ZTN78)
x
CP Failure
x
No Voice
x
Station OS
Analog Line (TN742)
x
CP Failure
x
No Voice
x
Station OS
MET Line (TN735)
x
CP Failure
x
No Voice
x
Station OS
Loop Start (ZTN77)
x
CP Failure
x
No Voice
x
Trunks OS
Grd Start (ZTN76)
x
CP Failure
x
No Voice
x
Trunks OS
DID Trk (TN753)
x
CP Failure
x
No Voice
x
Trunks OS
Tie Trk (TN760B)
x
CP Failure
x
No Voice
x
Trunks OS
Aux Trk (TN763)
x
CP Failure
x
No Voice
x
A
UX
.
Eq. OS
Data Line (TN726)
x
CP Failure
-
-
-
-
Tone Det (TN748)
x
Tone Failure
- - -
-
Legend:
Notes:
1
CP—Circuit Pack
ETU—Emergency Transfer Unit
OS-Out-of-Service
X—indicates that the voltage is used by the associated CP.
.
Ringing voltage (not
shown
on table) is used by the ZTN78 and TN742
CPs. Associated stations will not ring if a ringing voltage problem occurs.
2. TN746B same as TN742
3. TN747 same as ZTN76 and ZTN77
4. TN762 same as ZTN79.
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