HP 3575A User Manual

I
Model
3575A
TBO
UBLESHOOTING
Additiona.l
checks
can be
peformed
using
the
power
supply
data listcd
in Table
5-6. lf
any
of
the supply
yoltages
are
out
of
tolerance, troubleshoot
the conesponding power
supply
or
regulator
circuit
by checking for
the dc voltages
shorvn
on the schematics.
NOTII
All
of the
rc& ators on Al4
ore
directb or iulirectly
referencet)
to
+
12Vdc. The
+
12 Vclc
referance
nuts't,
therefore,
be
properly
acljLtsted to
estqblisll
the acato(!
of
the
othcr
suppll' voltages. 1n
qddition,
all of tha lC
regulqtors
ofi Al4
use
+
12 Vd(
and
-
l2
Vdc
ontl
a
failura
in
either of these supplics
can
affect the other
supph,
voltages.
5-89.
No Load
Checks. The Porver
Supply
Asscnrbll,,
A14,
is cquipped
with
separatc input
and output
connectors
to
permit
the supplies
to be checked
under no load
conditions.
The
2xl0-pin
connector on
the
left-hand
side of Al.l
receives uruegulatcd
inputs from
the raw
supplies on
Al5.
The l2-pin
cornector on
the right-hand
side of
A14
outputs
the regulated
voltages from
Al4 to
the main
Mother Board
Assembly,
Al7.
5-90.
To
chcck the
supplies
under
no load
conditions.
proceed
as follorvs:
a.
Place
Al4
on
a 2Xl0-pin PC
Extender (-hp-
5060-5987).
Leaye the l2-pin
output
oonnector discon-
nected.
b.
Corurect
a short clip lead
betwecn
chassis
ground
and
pins
l1
and l2ofthe
12-pio
cornrector on
Al4.
c.
Using
a
DC
voltmeter,
measure
the regulated
output
voltages
at
pins
4 th'rough
10 of the
12-pin connector
on
A14. The dc
voltages should
bc
as
follows:
Section
V
suppiies.
If
dilflculty
is encountered,
check
suspected
componcnts
with
an ohnteter
or
transistor
checker,
rcplace
Al4lCl
and IC2
or
isolate
thc trouble
using
an extental
dc
source
as
outlined
in
the followirg
procedurc:
RECOMT,IENDED
EQUIPMENT:
DC
Di8ital Voltmeter
(-hp-
Ntodel
34504)
1
l2
Vdc
Variable
Power
Supply
(hp-
Model
4674)
a.
Check to
be
sure
that
the raw
supply voltages
are
present
at XAl,lA
pins
9
(+
19 Vdc)
and
B (
l9 Vdc).
b.
Dsconnect one end
of
A14Rl.
c.
Place
Al4
on
a 2Xl0 PC Extender
(-hp"
5060-5987).
Lfave
the l:-pin outpul.
cunlector
disc.rnnccted.
d.
Connect
a short
clip lead
between
chassis
gound
and
pins
I I
and l2
of
the l2-pin
connector on
Al4.
e.
Connect
the
DC Dgital
Voltmeter
to
pin
9 of
the
I
?-pin
connector on
Al4.
f.
Apply
+
12 Vdc from
an exterral power
supply
to
pin
l0 ol the
l2-pin
conneotor on
Al4.
g.
Thc
DVM
reading
should
not
be
-12
V
dc. If
'
l2
V
dc is
present,
leave
the extcrnal porver
supply
connscted
ard
troubleshoot
the
+
l2 V
rcgulator
circuit
by
checking
for the
dc voltagcs
shown
on Schenratic
No.
g.
If
-
l2 V
dc
is no1
prcsent,
perforDr
the iirlloivilg
steps.
h
Disoonnect
the
external
power
supply
and reconnect
AlzlRl.
Dsconncct
one end
of
Al4R8.
i. Connect
the DVM
to
pin
l0 of
the I
f-pin
conlector
on
Al4.
j.
Apply
-
l2 Vdc from
an extunal power
supply
to
pin
9 of
the
l2-pin
connector
on
Al4.
k.
The DVM
reading
should now
be
+
12Vdc.
If
+12Vdc
is present,
leave
the external
power
supply
connected
and troubleshoot
the
-
I2 V regulator
circuil by
checking
for
the
dc voltages
shown on
the schematics.
if
+
l2
Vdc
is not present,
there
are failures
in
both regulator
cilcuits.
4
5
6
7
8
I
10
+5V10.02Vdc
-
5.3
V 1
0.1 Vdc
6V1o.o2Vdc
-6Vl0.02Vdc
+
3.8
V
1
0.1 Vdc
12
V
10.04
Vdc
+'12
v r 3 mvdc
*
5-91.
Troubleshooting
the
+
12
Due
to thc interactiolt
belween
supplies, it
is sontetinres
di[ficult
*
Adiustable
V
and
-
12
V Supplies.
the+12Vand-12V
to
isolate
lailurcs in
thesc
*
Adjustable
(A148
6)
**
Load increases
to 1
.5 A in
Option 001 insiruments
and to
2 A
in Option 002, OO3
instruments.
Table
5-6.
Power
Supply
Ratings.
Supply
T€st
Point
Voltage
Limit
Ripple
{p-pl
L ine
Regulation
i'115
V
1230V
!
10 %t
Nominal
Current
+
12
V
*
.12
V
6V(A)
-6V(B)
+5V
-5.3V
+3.8V
ATPl Pin
6
A7P1 Pin
D
A7P1 Pit
4
A7P1 Pin
21
ATPl Pin
3
+11.997Vto+12003V
-
1 1
.960 V to
-
1
2.040 V
5.980
V ro
6.020 V
-5.980
V
to 6.020 V
+
4.980 V
to
+
5.020
V
-
5.2oo V to
-54oov
+
3.700 V
to
+
3.900 V
3mV
10.1
mV
r
0.1 mV
10.2
mV
180 mA
180 mA
2OO
mA
20O mA
35O
mA
3O0 mA
5.1 9

HP 3575A Specifications

General

Brand	HP
Model	3575A
Category	Measuring Instruments
Language	English