HP 3000 Series Installation And Service Manual page 44

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This section contains general servicing information for the HP
30010A Intelligent Network Processor (INP). This information
includes safety precautions, repair philosophy, maintenance aids,
use of the self-test capability, troubleshooting, and field-level
repair.
5-1. SAFETY PRECAUTIONS
Whenever the !NP printed circuit assemblies (PCAs) are being
installed or removed, ensure that the computer's SYSTEM DC POWER
switch and both MEMORY DC POWER switches are set to the STANDBY
position. (These switches are located inside of the main cabinet
door, behind the register displays.)
Whenever an INP PCA is being connected or disconnected to a modem
(by attaching or removing the !NP-to-modem interconnecting
cable), ensure that the SYSTEM DC POWER switch and both MEMORY DC
POWER switches are set to the STANDBY position and that the modern
power is also turned off.
Be particularly cautious when selecting the routing for the
longer lengths of the interconnecting data cables. DO NOT run
these cables outdoors! Lightning induced transients can have a
devastating effect on data communication links; and a more direct
lightning strike can, of course, be a very real safety hazard to
personnel as well as to the equipment. Indoor routing must be
planned to avoid sources of electrical "noise", such as arc
welders.
Failure to observe these precautions could result in damage to
the components of the
~ornputer
system, the !NP, and/or the modern.
5-2. REPAIR PHILOSOPHY
Field repair of an !NP PCA is limited to the replacement of the
Random Access Memory (RAM} chips. Any other malfunction must be
remedied on an exchange basis. To exchange the !NP PCAs, remove
5-1