Failure rates 25
Table 4 continued
-
Failure rates of circuit packs
PEC/NT
Description
Failure Rate
Code
per
lo6
hrs
Ql’C673 512K RAM Memory Card 5.04
QPC674 256K Memory
with
Error 5.80
Correction
QPC706 Half PE Expansion Power 1.14
QPC710
QPC720
QPC723
Converter,
ist
tier
p-Law Digitone Receiver
Primary Rate Interface Card
RS-232 Interface Line Card
5.20
6.00
N/A
1
QPC757
1
D-Channel Handler Interface
1
N/A
1
QPC775 Clock Controller Card
2.44
Ql’C789
16-Port 500/2500 Line
N/A
I-
QPC814
QPC841
(Message Waiting)
Memory
Four-Port Serial Data
N/A
.
2.2
QPC918
QPC939
QPC940
Interface Card
High-Speed Data Card
Read-Only Memory
Read-Only Memory
N/A
N/A
N/A
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Spares planning 553-3001-l 53