HP 3000 III Series Manual page 361

HP 32435A SERIES III POWER SUPPLIES
I~
This section contains servicing information for the HP 32435A
Series III power supplies.
10-1. INTRODUCTION
The HP 32435A Series III Computer System has a maximum of five
power supplies; four power supplies in the CPU Bay and, if the
optional I/O Bay is installed, one power supply in the I/O Bay.
The HP 62605M-P3l/P4l, HP 633l2F-P02, HP 633l2F-P09, and HP
6l3l5D-P07 Power Supplies are located in the CPU Bay as shown in
figures 1-4 and 1-5. A second HP 62605M-P3l/P4l is located in
the I/O Bay of 2-Bay models as shown in figure 1-5.
10-2. POWER SUPPLY TROUBLESHOOTING
The HP 32435A Series III Computer System power supplies ar.e all
controlled and monitored by the Power Supply Cbntrol and Display
Assembly located at the lower front of the CPU Bay as shown in
figures 1-4 and 1-5. The Power Supply Control and Display Assem-
bly (f igur e 10-1) conta ins twel ve tes t point s (i ncl uding a common
ground) and associated LED indicators that monitor all the system
DC vol tage s p r ovi d ed by the p owe r sup plies. The te s t po i nts are
connected directly to the backplane voltages through a lK resis-
tor and can be used to measure any system DC voltage without en-
tering the rear of the equipment bay. The test point DC voltag-
es, associated power suppl ies, and purposes are 1 isted in table
10-1. It should be noted that the LED indicators located below
each test point do not "follow" the ir respective power supplies
and that their status (lighted or not lighted) has no meaning ex-
cept during a power supply failure. (Refer to the following text
and table 10-1 for additional information.)
In addition to the DC VOLTAGES test points and indicators, the
Power Supply Cbntrol and Display Assembly also contains three DC
STATUS indicators and two DC POWER switches located as shown in
figure 10-1. The functions of these indicators and switches are
listed in table 10-2.
If the DC POWER LOGIC switch is set to DISABLE, a power failure
is simulated so that the contents of memory will not be destroyed
and first the PFW indicator and then the PON indicator will no
longer be lighted. In addition, the DC VOLTAGES indicators will
be reset to their lighted status.
When the DC POWER switches are set to ENABLE, the PFW indicator
will light immediately if the system's inp~t AC power is within
specifications. After approximately one or two seconds, the PON
indicator will light if all the system's DC voltages are present.
10-1