AT&T Network Adapter 25 Installation And Maintenance Manual page 242

MAINTENANCE
Table 4-C.
Voltage/
Circuit Pack (Notes)
Call Proc. (ZTN82,
ZTN1 28) for RI
Memory (ZTN81,
ZTN1 27) for RI
CPU/Memory (ZTN129, x System Failure
for R2, ZTN130
for R3)
STARLAN (ZTN84)
Service Ckt (ZTN85
or ZTN131 (R3)
Hybrid Line (ZTN79)
Tip/Ring (ZTN78)
Analog Line (TN742)
MET Line (TN735)
Loop Start (ZTN77)
Grd Start (ZTN76)
DID Trk (TN753)
Tie Trk (TN760B)
Aux Trk (TN763)
Data Line (TN726)
Tone Det (TN748)
Legend:
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
Notes:
1
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.
4-66
Circuit Pack Voltage–Symptoms
+5 volts -5 volts
No+5 V
x x
EIA Failure x ETU Activated
System Failure
x System Failure -
x
EIA Failure
x
x CP Failure CP Failure -
x System Failure -
x No Voice x
x CP Failure
x x
CP Failure
x No Voice x
x CP Failure
x
x No Voice x
CP Failure
x No Voice
x CP Failure
x No Voice x
x CP Failure
x No Voice
x CP Failure
x CP Failure x No Voice
x No Voice
x CP Failure
x CP Failure -
x Tone Failure -
shown
on table) is used by the ZTN78 and TN742
-48 Volts
No-5 V No-48 V
- - -
x
ETU Activated
-
- - -
Station OS
No Voice x Station OS
Station OS
Station OS
x Trunks OS
Trunks OS
x Trunks OS
x Trunks OS
x A .
Eq. OS
UX
- -
-
- -
-