Table of Contents
HP 3242lA Series III Power Supplies
Note
Each time PFW goes low, the circuit must be
reset by increasing the ac input voltage to
208 vol ts.
h.
Set the ac input voltage to 160 volts.
PFW and paN
voltages
should
be low.
Increase ac input voltage to 180 volts.
PFW
should go high, followed by
paN
after
a
I-second
maximum
delay.
i.
Reduce ac input voltage to zero.
pos i tion.
Set
POWER
switch to
OFF
j.
Unplug ac line cord from autotransformer.
Plug into ac power
receptacle.
9-18. HP 30310A Troubleshooting
Troubleshooting in the field is limited to visual checkout, volt-
age checks, alignment, and power supply replacement if necessary.
Proceed as follows:
a.
Open rear door of cabinet and observe that the
POWER
switch
is set to ON and that the indicator light is lighted.
If the
switch is ON but the indicator is not lighted, the
indicator
is
defective or ac input power is not available to the power
supply.
Check the fuse.
b.
With the power on,
observe that the +5-volt red indicator is
lighted.
If it is not lighted, check that the DCE signal at
terminal of TB3 is low and that the indicator is good.
c.
Use the procedure in paragraph 9-13 to check the output volt-
ages of the power supply at the test points furnished on
the
front panel.
If the voltages
are not correct,
follow the
appropriate
adjustment procedure in
para~raphs
9-14 through
9-17.
d.
Replace the
power supply if it remains
inoperative or
does
not respond to al ignment.
9-19. HP 30311A OPERATION
The HP 303llA Power Supply
(figure 9-1) provides the semiconduc-
tor memory
with backup
battery power
during the absence
of ac
input power.
The volatile nature of dynamic
MaS
semiconductor
memory requires this backup power to prevent data loss.
The pow-
er supply receives its input power from the
HP 303l0A Power Sup-
ply and, in turn, provides backup battery power for main
memory.
The HP 303llA is a self-conta ined modular unit.
It occupies one-
half of a standard 19-inch rack mounting as shown in figures
1-2
and 1-3.
If only one power
supply is mounted in the system,
a
filler panel is supplied.
The
filler
panel
extends
the
full
9-11
Chapters
Table of Contents
Troubleshooting
