IBM 7133 Series, Service Manual

Page: 78 / 230

8
If any fan-and-power-supply assembly has no continuity, exchange that
fan-and-power-supply assembly for a new one (see “Fan-and-Power-Supply
Assemblies” on page 3-32), then do the complete grounding check again.
If each fan-and-power-supply assembly has continuity, you might have a problem
with the power cable or with the grounding of the using system.
9
Check the power cable for continuity.
If the power cable does not have continuity, exchange it for a new one, then do the
complete grounding check again.
If the power cable does have continuity, see the using-system Installation and
Service Guide to isolate the fault.
|
Grounding Check (Model 020 with
−
48 V Fan-and-Power-Supply
|
Assemblies)
|
1
Ensure that all power is removed from the rack (see the Installation and Service
| Guide for the using system).
|
2
Ensure that the power cables
1
and
2
are plugged into each
| fan-and-power-supply assembly. Ensure also that the other ends of the power
| cables are connected to the
−
48 volt supply in the rack.
|
3
Attention: Some electrical circuits could be damaged if the external SSA cables or
| power-control cables are present at the 7133 while the grounding check is being
| done.
| Ensure that no external SSA cables are present at the eight connectors
3
.
|
4
If the 7133 has a Remote Power On Control feature, go to step 5 on page 1-65.
| Otherwise, go to step 6 on page 1-65.
1-64
7133 Service Guide